Whole Number 293
THE
JOHNS HOPKINS
IJNFVERSITY CIRCULAR
741 $
CONTRIBUTIONS TO
GE-LOGY
AND
PLANT PHYSIOLOGY
BALTIMORE, MARYLAND
ISHED BY THE UNIVEBSITY
ISSUED MONTHLY FROM OCTOBER TO JULY
MARCH, 1917
Entered, October 21, 190C, at Baltimore, Md., as second class matter, under
Act of Cengu. of July 16, 1894
BERKELEY
LIBRARY
UNIVERSITY Of
CALIFORNIA
— i I.
EARTH
EXCHANGE
CONTRIBUTIONS TO
GEOLOGY
AND *
PLANT PHYSIOLOGY
t
BALTIMORE
THE JOHNS HOPKINS PRESS
1917
--EART*
SCIENCI
UBRARt
THE JOHNS HOPKINS UNIVERSITY CIRCULAR, No. 293
MARCH, 1917
GECvLOGY : *
CONTENTS
PAGE
••* .'Gfeofrgicat Surveys Vith Special Reference to the Work of the Maryland Geo-
•.•• • * • jlggjg^l.'Survty*. W. B. CLARK
3
The Use of Average Analyses in Defining Igneous Rocks. E. B. MATHEWS. ... 12
The Delta Character of the Tuscaloosa Formation. E. W. BERRY ......... 18
The Role of Mineralizers in Ore Segregations in Basic Igneous Rocks. J. T.
SINGEWALD, JR ................................................... 24
The Environment of the Tertiary Marine Faunas of the Atlantic Coastal Plain.
J. A. GARDNER ................................................... 36
The Pelecypods of the Bowden Fauna. W. P. WOODRING ................... 44
Origin of the Natural Brines of Oil Fields. F. REEVES ................... 57
An Upper Cretaceous Seacoast in Montana. W. T. THOM, JR ............. 68
A Remarkable Upper Cretaceous Fauna from Tennessee. B. WADE ......... 73
The Occurrence of the Tuscaloosa Formation as Far North as Kentucky.
B. WADE ........................................................ 102
The Habitat of Belemnitella Americana and Mucronata, G. E. DORSET ...... 107
PLANT PHYSIOLOGY:
The Department of Plant Physiology. B. E. LIVINGSTON ................. 133
Publications from the Laboratory of Plant Physiology, 1909-1917 ......... 154
Atmometric Units. B. E. LIVINGSTON ................................... 160
The Vapor Tension Deficit as an Index of the Moisture Condition of the Air.
B. E. LIVINGSTON ............................................ ..... 170
Incipient Drying and Temporary and Permanent Wilting of Plants, as
Related to External and Internal Conditions. B. E. LIVINGSTON ........ 176
The Effect of Deficient Soil Oxygen on the Roots of Higher Plants. B. E.
LIVINGSTON and E. E. FREE ....................................... 182
The Experimental Determination of a Dynamic Soil-Moisture Minimum. H.
E. PULLING ................................................... . . 186
Some Unusual Features of a *Sub- Artie Soil. H. E. PULLING ............. 188
The Geographical Distribution of the Citrus Diseases, Melanose and Stem-end
Rot. H. S. FAWCETT ............................................. 190
Preliminary Note on the Relation of Temperature to the Growth of Certain
Parasitic Fungi in Cultures. H. S. FAWCETT ....................... 193
Symptoms of Poisoning by Certain Elements, in Pelargonium and Other
Plants. E. E. FREE .............................................. 195
The Effect of Aeration on the Growth of Buckwheat in Water-Cultures. E. E.
FREE ..... ....................................................... 198
The Effects of Certain Mineral Poisons on Young Wheat Plants in Three-Salt
Nutrient Solutions. E. E. FREE and S. F. TRELEASE ................. 199
Leaf-Product as an Index of Growth in Soy-Bean. F. M. HILDEBRANDT ..... 202
A Method for Approximating Sunshine Intensity from Ocular Observations of
Cloudiness. F. M. HILDEBRANDT ................................... 205
Moisture Equilibrium in Pots of Soil Equipped with Auto-Irrigators. F. S.
HOLMES ......................................................... 208
Seasonal Variations in the Growth-Rates of Buckwheat Plants under Green-
house Conditions. E. S. JOHNSTON ................................. 211
On the Relation of Chlorine to Plant Growth. W. E. TOTTINGHAM ......... 217
A Study of Salt Proportions in a Nutrient Solution conaining Chloride, as
Related to the Growth of Young Wheat Plants. 'S. F. TRELEASE ....... 222
The Relation of the Concentration of the Nutrient Solution to the Growth of
Young Wheat Plants in Water-Cultures. S. F. TRELEASE ......... • ..... 225
The Effect of Renewal of Culture Solutions on the Growth of Young Wheat
Plants in Water-Cultures. S. F. TRELEASE and E. E. FREE ........... 227
THE
1 *>^ * n •'
JOHNS HOPKINS., V
UNIVERSITY CIRCULAR
EDITED BY THOMAS E. BALL
New Series. 1917, No. 3 MARCH, 1917 Whole Number, 293
CONTRIBUTIONS TO
GEOLOGY
GEOLOGICAL SURVEYS WITH SPECIAL REFERENCE
TO THE WORK OF THE MARYLAND
GEOLOGICAL SURVEY 1
By WILLIAM BULLOCK CLARK
A discussion of the organization and work of a Geological
Survey would not be complete without some introductory
words regarding the origin of geological surveys.
Geological knowledge has been advanced by the individual
working independently either in a private capacity or under
university or similar auspices,, or by a group of individuals
brought together in an official organization, controlled gen-
erally in large measure by the lines of investigations to be
followed. Cooperation is of course possible in the first case
but not absolutely necessary, while team-play is an essential
1 Part of a discussion before the Scientific Association of the Johns
Hopkins University.
201] 3
854788
4 Geological Surveys [202
feature of the Survey no matter how much independence may
be granted in individual instances.
Although;, individual effort of a sporadic sort had long
not until the appointment of Werner in 1775
ast J^ofQSsor at. Freiberg in Saxony that geology can be said
\tcf ^a^etSeeriv'recognized as an independent science and
admitted as such into academic surroundings. The great
influence of Werner in securing recognition for geology,
although many of his conceptions were erroneous, has led to
his being called the Father of Geology. For a half-century
after his time much work was done by private initiative both
in and out of the university to advance the science of geology,
but it began to be recognized more and more that individual
resources were inadequate to secure the vast number of facts
in the field on which most lines of geology depend. It was
then that public aid was solicited and secured, but secured
not wholly because the legislator was impressed with the pos-
sibility of advancing geology for its own sake but because the
geologist was able to impress him that out of this work some-
thing of a practical nature might be speedily or in the more
distant future secured. It is unfortunate, perhaps, that the
geologist, if he is to secure public support for such work, must
be to some extent what is called a lobbyist, although the time
and energy employed are not wholly lost in that his vision is
broadened by frequent contact with men of affairs. Not all
representatives of the people, to be sure, consider the public
interest of first importance, but there are always some, often
many, who do ; at least that has been my experience.
It is to America that we have to look for the first recogni-
tion of the part the public may play in the support of geologi-
cal work through legislative appropriations, and it was North
Carolina that established the first official Geological Survey.
This was in 1823, when the General Assembly of the State
authorized the Board of Agriculture to pay the expenses of
" geological excursions " for a period of years and appointed
Professor Denison Olmsted, of the State University, subse-
203] W. B. Clark 5
quently Professor at Yale, to direct the work. South Caro-
lina followed the example of its sister State in 1824 with
Lardner Vanuxem in charge; then Massachusetts in 1830 with
Edward Hitchcock as State Geologist, the first important
Survey, as the Carolina organizations were rather insignificant
affairs; then Tennessee in 1831 with Dr. Gerard Troost as
Geologist; then Maryland in 1833 with Jules T. Ducatel, a
graduate of the Sorbonne, as State Geologist, and J. T. Alex-
ander as State Topographical Engineer. Alexander has the
credit of attempting the production of the first topographical
maps in the country, and although they were very crude they
possess much of historical interest. In 1835 the Virginia
Survey was inaugurated with W. B. Eogers as Director, the
New Jersey Survey with H. D. Eogers in charge, and the Con-
necticut Survey with J. G. Percival and Charles U. Sheppard
as Geologists. The following year, 1836, saw the inauguration
of the important Survey of New York with such men as W. W.
Mather, Ebenezer Emmons, Lardner Vanuxem, Thomas A.
Conrad, and James Hall as Geologists, and of the Pennsyl-
vania Survey which secured H. D. Eogers from New Jersey,
and also the surveys of Georgia with John E. Cotting as State
Geologist, and of Maine with Charles F. Jackson at the head.
Following these come in succession the Surveys of Delaware,
Ohio, and Michigan in 1837, Ehode Island in 1839, New
Hampshire in 1840, Vermont in 1845, Alabama in 1847,
Mississippi in 1850, Illinois in 1851, Wisconsin and Florida
in 1853, Iowa in 1855, Arkansas in 1857, Texas in 1858, and
California in 1860, so that prior to the Civil War only a few
of the then existing States were without official Geological
Surveys. The leading men of their time in American geology
were in charge of this official work, organized at the public
expense. Hitchcock, Emmons, the Eogers brothers, Vanuxem,
Conrad, Hall, and the others I have named comprised the
chief workers of their day.
The Federal Government up to this time had done little to
subsidize geological research. Some explorations of the west-
6 Geological Surveys [204
ern country had been inaugurated in which geology consti-
tuted a part of the prospective plans. Among the more pro-
ductive of such investigations were those made by David Dale
Owen under the United States Land Office and Treasury
Department in the upper Mississippi valley region in Iowa,
Illinois,, Wisconsin, Minnesota, and Nebraska in various years
from 1839 to 1851 and by the distinguished geologists and
paleontologists Newberry, Marcou, Blake, Conrad, Hall, and
others in connection with the Pacific Eailroad Surveys from
1853-55 under the War Department.
Only a single foreign government had inaugurated official
geological work during the early portion of this period. The
Ordinance Survey of Great Britain in 1830 made a small
grant to H. F. De la Beche for the survey of southwest Eng-
land, but it was not until later that he was definitely appointed
to make a Geological Survey. Spain and Austria established
Geological Surveys in 1847 and 1849, respectively, but it was
not until the next decade that similar organizations were suc-
cessively established in Bavaria, Portugal, the Netherlands,
Norway, Sweden, and Switzerland. Some years passed before
the other foreign governments followed suit.
Following our Civil War the American Government, recog-
nizing the necessity of acquiring information regarding our
great western country, established four exploratory geological
organizations, two under the auspices of the War Department,
the U. S. Geological Exploration of the 40th Parallel under
Clarence King, and the U. S. Surveys west of the 100th
Meridian under G. M. Wheeler, and two under the auspices of
the Interior Department, the U. S. Geological Survey of the
Territories under H. V. Hayden and the U. S. Geographical
and Geological Survey of the Eocky Mountain Region under
J. W. Powell. They were finally combined in 1879 with the
title of U. S. Geological Survey, under Clarence King as first
Director, and this organization with appropriations exceeding
$1,000,000 annually is now conducting work in every section
of the country although devoting its chief energies to the
West.
205] W. B. Clark Y
At the present time nearly every State in the Union is also
carrying on its own official work,, generally with some form of
cooperation with the Federal organization.
The State Geological Survey of Maryland, as at present
organized, began its operations in the spring of 1896 and is
thus over twenty years old.2 Like many other similar organi-
zations the Maryland Survey is carried on in conjunction
with the geological department of its leading University. In
States where State universities exist they are often the head-
quarters of such work.
The primary object of a geological survey is to determine
and describe the geological formations and depict the results
on maps. In order to classify these formations intelligently
one must establish criteria for their discrimination based not
only on their original lithological and paleontological charac-
teristics but also on their often highly changed texture and
structure. In such a region as Maryland, which has repre-
sentatives of many types of rocks, nearly every phase of geo-
logical investigation is involved. For this reason it affords a
magnificent field of study for the student and has been so
employed in the training of several score of graduate students
at this University. The State also benefits in that it has at
its command many trained or partially trained men without
the expense of a permanent staff.
The differentiation of geological formations and their repre-
sentation on maps has passed through many interesting phases,
and a few words in this place regarding the history of geo-
logical maps may not be inappropriate. As far back as the
end of the 17th century a scheme for depicting the mineral
products of a country upon a map was submitted to the Eoyal
Society of London and appears in the Philosophical Trans-
actions under the quaint title of " An ingenious proposal for a
2 The Ducatel- Alexander Survey came to an end in 1842 and tho
only official State geological work of any importance carried on in
Maryland after that time until the organization of the present
Survey was by Philip T. Tyson who as State Agricultural Chemist
from 1858 to 1862, prepared the first geological map of the State.
Geological Surveys [206
new sort of Maps of Countrys, together with tables of sands
and clays,, such chiefly as are found in the north parts of Eng-
land, drawn up about ten years since, and delivered to the
Eoyal Society, March 12, 1683, by the Learned Martin Lister,
M. D." 3 The first attempt at a geological map was appar-
ently made by Christopher Packe in 1743 when he published
with an accompanying tract "A new philosophic chorographi-
cal Chart " of East Kent, England, covering an area of about
thirty- two square miles. The object of the map was chiefly
to delineate the topography and agricultural soils, while the
geological indications are confined to notices of the position
of sea beaches, gravel pits, chalk pits, etc.
Much more complete maps of this character covering chiefly
northern France on which the mineral substances were
grouped in bands were communicated in connection with a
memoir by Guettard in 1746 to the Academy of Sciences of
Paris.4 Following these came maps of the same character by
Fiichsel5 in 1762, by Guettard and Lavoisier about 1770,
when twenty-nine uncolored geological sheets of the map of
France were issued; by Guettard and Monnet in 1780, when a
folio of thirty-two sheets accompanying a mineralogical de-
scription of France was published, and by Desmarest in 1771,
when an uncolored Geological Map of the Auvergne was
prepared.6
The first colored geological map is the work of Glaser, who
in 1775 depicted in colors a small district in Saxony about
twenty miles long by fifteen miles broad, three tints being
used : red for granite rocks with a blue dotted line to distin-
guish apparently one kind of crystalline rock from another,
yellow for sand, and gray for limestone. Factories, limekilns,
and coal, iron, copper, silver, and gold deposits were indicated
by signs.
3 Phil. Trans., vol. xiv, p. 739.
*Mem. Acad. Roy. Frcmce, vol. for 1746, pp. 343-392.
5 " Historia Terrae et Maris, etc." Acta Acad. elect. Moguntinae
1762, pp. 44-209.
6 Mem. Acad. Roy. France, vol. for 1771, pp. 705-775.
207] W. B. Clark 9
In 1778 Charpentier7 published a book on the mineralogy
of Saxony accompanied by a so-called petrographic map on
which red is used for granite, purple for gneiss, pink for
schists, blue for limestones, gray for gypsum, yellow for sand-
stone, drab for river sand, and green for clay and loam.
Palassou in 1781 8 published an essay on the Mineralogy of
the Pyrenees in which the routes in the south of France are
colored according to the rocks they cross : green for granite,
yellow for schists, and red for limestone, while sands, sand-
stones, and clays are indicated by signs, as are also extinct
volcanoes.
Much the most important of these early colored geological
maps were those of William Smith, who prepared fifteen
county geological maps of England between 1794 and 1821.
These and his general geological map of England published
in 1815 mark the beginning of modern geological cartography.
Many refinements have been introduced in subsequent years
and an attempt more or less successful has been made to
secure cooperation on the part of geologists the world over in
the use of the same colors for rocks of the same age and char-
acter. At first all maps were colored by hand, but in recent
years lithographic processes have been introduced, although
the Geological Survey of Great Britain continued to color its
geological maps by hand until a few years ago. The Mary-
land Survey has made only colored lithographic geological
maps.
In addition to the strictly geological work carried on by the
instructors and students of the Geological Department to
which I shall again presently refer, the Survey has secured
the cooperation of the staffs of several Federal and State
Bureaus (1) in the making of the base topographic maps,
necessary not only for the geological but other kinds of sur-
veys; (2) in the classification and platting of the agricultural
soils which are the disintegrated surface portions of the geo-
Mineralogische Geog. d. Chursachsische Lande, 1778.
Essai sur la Mineralogie des Monts Pyrenees, Paris, 1781.
10 Geological Surveys [208
logical formations combined with vegetable debris or humus ;
(3) in determining the magnetic elements of variation,
declination, and force so much affected by the underlying
rocks, and (4) in the study of the surface and underground
waters so largely dependent on the geological structure. In
addition to these lines of work the Survey was directly con-
cerned in the past in organizing the modern methods of state
highway construction which were introduced in 1898, and for
ten years thereafter it was the only state agency intrusted with
this important service and until the transfer of its Highway
Division in 1910 to the newly-organized State Roads Com-
mission, on which it also had, by law, influential representa-
tion until 1914. During this time the Survey built 150 miles
of public highways at an expenditure of nearly $1,500,000, but
more than that, developed standards of work and a trained
engineering force that today largely control this important
public enterprise.
The Survey has also participated in the re-surveys of many
of the state boundaries, including the re-survey of the Mason
and Dixon Line, and also of several county boundaries. It
has made extensive geological and mineral exhibits at the Buf-
falo, Charleston, St. Louis, Jamestown, and San Francisco
Expositions, the more important materials then secured being
today maintained as a permanent exhibit in the Old Hall of
Delegates in the State House at Annapolis.
Returning now to the strictly geological work of the Survey,
I wish to call attention to the fact that some of our official
organizations, carried away by the clamor for immediately
practical results, are devoting their time much more than in
the past to present commercial needs, ignoring the fact that
their greatest service to the public is in studying the funda-
mental scientific problems furnished by the rocks even when
they appear to afford no application to the industries of today.
I feel that a Survey that is continually thinking of the practi-
cal results it can secure should not have the name of geologi-
cal, for I dislike to feel that geology has no higher public
209] W. B. Clark 11
value than to provide means for the shrewd business man who
may employ its results to acquire a few more dollars. It is my
belief that if the work of a Geological Survey is properly done,
with one regard to the solving of the scientific problems as
they arise, it will indirectly do the commercial interests of the
community a greater service in the end than if the practical
aspects of the work are given first place. It would not be diffi-
cult to demonstrate this in the case of our Geological Surveys
if I had the time.
Maryland possesses three provinces : first the Coastal Plain
which consists of the low-lying country extending from the
ocean front to a line drawn through Elkton, Havre de Grace,
Baltimore, Laurel, and Washington, which consists of nearly
unaltered sediments of relatively simple structure, the basal
members of which date well back in geological time, in fact,
before the Eocky Mountains or the Alps were formed. They
afford a series of problems of great interest but quite different
from those of the other areas.
Lying to the west of the landward border of the Coastal
Plain and extending to the base of the Catoctin Mountain is
a second area known as the Piedmont Plateau consisting of
highly metamorphosed crystalline rocks cut by intrusive and
extrusive eruptive rocks, the whole subjected to extensive
deformation with intricate folds and faults. The rocks are
very old and probably comprise the southern extension of the
great Canadian shield, the oldest portion of the North Ameri-
can continent. Here are problems of great interest to be
solved.
Beyond and extending to the western limits of the State is
a third area known as the Appalachian Eegion that contains a
great thickness of deposits lying in large part intermediate in
position both as regards age and structure between those of the
Coastal Plain and the Piedmont Plateau. Along their east-
ern margin they are metamorphosed, folded, and faulted with
a large admixture of eruptive rocks that become progressively
less complicated westward. In this district still other prob-
lems are presented.
12 Analyses of Igneous Rocks [210
I might go on and enumerate in much greater detail the
innumerable questions which such an area as Maryland pre-
sents to the geologist. We have been engaged, as I stated
earlier, for over twenty years in trying to reach a solution of
some of these problems, but our successors will, I am sure,
find enough to keep them fully occupied for another genera-
tion if it is not vouchsafed for us to keep actively employed
in studying them during that time. The question may be
asked, is often asked by the custodians of the public funds,
will this work never end ? But I must answer no, not as long
as there is a science of geology worthy of the name.
THE USE OF AVERAGE ANALYSES IN DEFINING
IGNEOUS ROCKS
By EDWARD B. MATHEWS
There is usually associated with the consideration of rock
names and their meanings some attempt to represent the
characteristic chemical composition connoted by the name.
The methods employed usually /consist of the presentation
either of a series of analyses of individual rocks with little or
no discussion of their meaning or of an arithmetical mean of
a varying number of such analyses in the form of an " aver-
age " analysis also without discussion of the departures from
such averages which may be shown by the analyses on which
this " average " is based. Neither of these methods is very
satisfactory for teaching or textbooks.
The presentation in columnar form of a series of analyses
each of which includes from eight to fifteen determinations
bewilders the student who seldom stops to consider just what
the variations amount to either absolutely or relatively, or
what relations the variants bear to the general type. This
method of enumerating the actual composition of individual
rocks may be eminently proper in a Handbook but fails of its
purpose in a textbook.
211] E. B. Mathews 13
The presentation of a single " average " analysis possesses
all the charm of simplicity and ease of comprehension but
fails to convey a proper conception of the complex variability
underlying it. The student, with retentive memory, may hold
the values assigned to the type but may gain thereby little
knowledge of the real content of the term. If the rock se-
lected is in itself sharply defined., or if the examples collected
are sufficiently numerous the " average " analysis may be
satisfactory. If, on the other hand, the individual rocks in-
cluded under a given name are aggregates of minerals of vary-
ing composition in various proportions such as might occur in
a complex of numerous related and unrelated continuous gra-
dations without any semblance of "clustering," then the
" average " analysis gives nothing more than the arithmetical
mean of the quantities which have been included. As Cross x
remarked in his criticism of the classification proposed by
Loewinson-Lessing, " the grist of this mill depends entirely
upon what is put into the hopper."
While even a momentary consideration shows that what has
been said regarding individual concepts applies even more
strongly to group concepts, the writer has considered it worth
while to test quantitatively the variabilities actually involved
in " average " analyses. The test is limited to anorthosites
and non-feldspathic pyroxenites and peridotites and the
methods employed are both graphic and arithmetic.
EXAMPLES
Anorthosite is composed of approximately a single mineral
or at least of representatives of a single isomorphous series.
The natural presumptions are that their analyses would repre-
sent a continuous series and their -average an intermediate
member. A graph of the analyses found in the literature
shows no such evenly distributed series, at least so far as lime
and soda are concerned, but three distinct types; one with
1J. Geol., vol. X, 1902, p. 481.
14 Analyses 'of Igneous Rocks [212
approximately 16% CaO, the most abundant with approxi-
mately 10% and a third with about 3%%. While the usual
" average " analysis of anorthosite would represent in a gen-
eral way the more abundant variety the breadth of range, the
discontinuity of the series and the existence of grouping is
obscured.
Dunite (Fig. 1) is another rock consisting largely of a single
mineral. Here the analyses shows little variation except in
the ferrous iron which shows an absolute range of 10% and a
relative range of 156% of its mean amount. Magnesia shows
an absolute range of 7% or about 15% of the average content.
The isomorphism of the olivine group would suggest more
uniform departures of the iron and magnesia from their aver-
age values.
Horriblendite (Fig. 2) is a third representative of rocks
composed essentially of a single mineral or mineral group.
Here the possibility of alumina in the molecule suggests
wider departures from the average but the analyses show an
absolute range in alumina of scarcely 9%, although nearly
80% of the average content. Ferric iron shows about the
same absolute range but a much greater relative range because
of its lower average content. Ferrous iron, on the other hand,
with an average content similar to that of alumina, shows a
relative range of 175%, while magnesia and lime show total
ranges of less than 100% of the average content.
From the foregoing it seems reasonable to infer that con-
clusions based upon " expansions " of averages in accordance
with the known isomorphism of constituent minerals are un-
certain even in monomineralic rocks.
Turning to rocks consisting essentially of olivine with one
or more pyroxenes or hornblende two rocks were selected.
Uarzburgite or Saxonite (Fig. 4) composed of olivine and
an orthorhombic pyroxene shows several variant types which
are entirely obscured in an average analysis. The rocks which
have been named harzburgite compared with those called
Saxonite generally show lower alumina and lime with higher
213]
E. B. Mathews
J5
FIG. 1 TO 8.
Graphs showing composition of igneous rocks used in obtaining
average analyses.
16 Analyses of Igneous Rocks [214
magnesia and similar silica, ferric and ferrous iron. These
variants may be due to chance and their distinctness to
paucity of example, but such differences as may exist are
obliterated by the use of an " average " or even " typical "
analysis.
Lherzolite (Fig. 3) consisting of olivine, bronzite and
diallage shows on the whole a wide but uniform distribution
in the content of the various constituents in the analyses at
hand. The graph shows the abnormality of the Iherzolite
from the Protrero, San Francisco with its low magnesia and
high lime which raises a question as to the applicability of
its name.
All of the examples thus far considered have been named by
workers of different experience and training and the sugges-
tion comes that the variations in composition are due in part
at least to incomplete comprehension of the content of the
terms used or to personal variations in usage. To illustrate
range acceptable without these factors two sets of examples of
unique types studied by single workers were selected.
Koswite. Composed essentially of olivine and magnetite
with diopside, and some hornblende, and chromite includes a
series of magnetite pyroxenites described from the Urals.
They are characterized chemically by high ferric and ferrous
irons. While the analyses are incomplete through lack of
alkalies their summation is in every instance over 100, show-
ing that this lack does not vitiate them for the present
purpose.
The departures from the mean of values for the individual
constituents is here usually only two or three per cent, or less
than 50% of the value of the dominant constituents.
Ariegites as defined by Lacroix are a group of pyroxenites
characterized by the constant association of one or more
pyroxenes and a spinel with varieties due to the presence of
garnet and hornblende.
In this series the absolute range is 4% to 8% and the de-
partures in the case of the principal constituents is not over
10% of the mean values.
215] V. B. Mathews 17
From the foregoing it would appear that mature workers
even in establishing their types believe it allowable to include
rocks whose dominant constituents show departures ranging
from 10% to 30% from their mean values.
The use of average analyses in the description of rock
groups may or may not prove more serviceable. "While there
are more possible variations in the kinds and proportions of
minerals the graphs may show no wider variations than those
noted in discussing individual types. Thus the diagram
(Fig. 7) showing pyroxenites, exclusive of the websterites
(Fig. 8) although representing several kinds and many ex-
amples of pyroxenites, is not much more confusing or variable
than that for the websterites by themselves. The peak for
lime is more marked but the predominance of the magnesia
and lime with the subordination of the irons and alumina are
nearly as clear. The more general diagram carries aberrant
types like the pyroxenite from Rosetown, N. Y. (high alumnia
and low magnesia) and the magnetite pyroxenite from Cen-
tral City, Colo, (high in irons) . The former is a poor analy-
sis while the latter is recognized as aberrant and their inclu-
sion in any general average analysis is doubtful.
Similar graphs of gabbro, dacite and camptonite show
fairly well defined figures which indicate that the impressions
gained from average analyses while incomplete may not be
incorrect in the major essentials. Average analyses cannot be
expected to bring out minor " clusterings " or many of the
relationships in constituents which are disclosed by the simple
serial diagrams here employed.
The same is true of several of the systems of projection now
employed in petrography. These, moreover, often require ex-
perience and maturity beyond that of the average student of
systematic petrography for their complete appreciation.
18 Tuscaloosa Formation [216
THE DELTA CHARACTER OF THE TUSCALOOSA
FORMATION
BY EDWARD W. BERRY
During the enormous interval of time represented by ma-
rine sediments in other parts of the world of late Carboni-
ferous, Permian, Triassic, Jurassic and Lower Cretaceous
ages the southern Appalachian region was above sea level.
Physiographically the southern half of this region is segre-
gated at the present time into the Piedmont Plateau, the
Appalachian Mountains (which die out in northwestern
Georgia), the Appalachian Valley, the Cumberland Plateau,
and the Interior Lowlands. Its area south of the Ohio Eiver
is over 160,000 square miles, and the actual area of this land
mass during the interval from the Carboniferous to the Upper
Cretaceous must have been very much greater than this, since
nowhere along the margins of this massif have marine sedi-
ments of these ages been deposited near enough to its present
limits to be reached by deep borings near the margin of the
present Coastal plain.
The region of the southern Appalachians is one that has
long interested physiographers. Hayes and Campbell, the
chief contributors,1 have recognized three base levels or
peneplains which they term in the order of their ages the
Cumberland, the Highland Rim and the Coosa. They con-
sider that the original Tennesee River, which they term the
Appalachian Eiver, flowed southwestward by way of the valley
of the Coosa Eiver throughout the Upper Cretaceous and the
major portion of the Tertiary until it was diverted by stream
capture due to the working back across Walden Eidge of a
stream in the Sequatchie valley to the west of that ridge.
1 Hayes, C. W. and Campbell, M. R., "The Geomorphology of the
Southern Appalachians," Natl. Geographic Magazine, vol. 6, pp. 63-
126, 1894; Hayes, C. W., "The Physiography of the Chattanooga
District," U. S. Geol. Survey, 19th Ann. Rept., Ft. 2, pp. 1-58. 1899.
217]
E. W. Berry
19
This spectacular river capture has been disputed by Johnson 2
who, it seems to me, conclusively demonstrates that the pre-
sent course of the Tennessee River across Walden Ridge in a
winding gorge is imposed from meanders inherited from the
FIG. l.
Map showing physiographic regions and areas of outcrop of
Tuscaloosa, Eutaw, and Selma formations.
period of earliest complete baselevelling in this area, namely
from the Cumberland peneplain.
The character of the Upper Cretaceous sediments of the
eastern Gulf area throw considerable light on the physical
2 Johnson, D. W., " The Tertiary History of the Tennessee River..'
Jour. GeoL, vol. 13, pp. 194-231, 1905.
20 Tuscaloosa Formation [218
history which has interested me chiefly in connection with the
interpretation, in terms of geologic history, of the extensive
fossil floras that have been found in the earliest Upper Creta-
ceous or Tuscaloosa formation of this region.
The Tuscaloosa formation in the area around Tuscaloosa,
Alabama, and for some distance to the northwest consists of
about 1,000 feet of predominantly sandy materials which
give the country its present topography. These sands are
usually light in color, cross-bedded and micaceous — occasion-
ally there are traces of glauconitic layers. There are heavy
beds of gravel made up of well rounded quartz and sub-
angular chert pebbles in about equal proportions in places,
especially toward the landward margin of the deposits and
northward along the strike. In disconnected and interbedded
lenses there is a considerable amount of argillaceous material
— at times massive or heavy bedded, but generally laminated.
Thin seams of lignite are present at various levels but these
are generally only a few inches or less in thickness. The clays
are often oxidized and mottled in color but they are as fre-
quently very carbonaceous and dark in color. In some sec-
tions, as in the Big Gully section southwest of the town of
Tuscaloosa, there are layers filled with prostrate logs of trees
of large size. Pyrite and ferruginous oxide, forming locally
indurated sandstones and gravels are generally distributed,
and finely disseminated gypsum crystals are very common.
No fossils other than the remains of land plants have been
found in the Tuscaloosa deposits. Usually the plant remains
are much macerated and broken by water transportation and
deposited in films of broken fragments in the laminated beds.
Drift logs are common and these occasionally brought down
cobbles imbedded in their roots (statement based on speci-
mens collected in lignitized tree roots). There appear to
have been areas of quiet waters at certain localities where the
leaf remains in the clays are abundant and in a state of
preservation indicating that they grew in the immediate
vicinity.
The outcrop of the Tuscaloosa formation, as shown in the
219] E. W. Berry 21
accompanying sketch map, is roughly lunate in outline with
the southeastern horn terminating near Montgomery, Ala-
bama, and the other extending as an attenuated band across
western Tennessee. As will be seen, the greatest width of
outcrop coincides with the maximum thickness of sediments
in a belt about 125 miles in length which is at right angles
to the axis of the Appalachian land mass. To the northward
the deposits become thinner, are prevailingly gravels and are
shown by the fossil plants to be somewhat younger than the
main body of the deposits.
In the interpretation of the Tuscaloosa deposits with their
gravels and compound oblique cross-bedded sands, their occa-
sional traces of glauconite and their abundance of driftwood,
one cannot fail to be impressed with their delta-like character.
We are now fairly familiar with the main features of delta
deposits in different parts of the world 3 and Grabau 4 and
Barrell5 have recently contributed considerable toward the
interpretation of Paleozoic delta deposits. Eeturning for a
moment to the physiographic history of the Tuscaloosa region
we find that there are no sediments later than Pottsville age
until the deposition of the Tuscaloosa in the earlier Upper
Cretaceous. This long interval resulted in the nearly com-
plete baselevel known as the Cumberland peneplain. There
must have been some regional uplift or warping at the begin-
ning of Tuscaloosa time to account for the sudden augmenta-
tion in river action and the inauguration of the large delta
or series of deltas along the southwestern margin of the land
mass. There is no evidence in the sediments that an Appa-
lachian river flower southwestward through the Coosa valley.
This would also have brought the bulk of the sediments far-
ther eastward than where they now occur. While I regard
Johnson's evidence (op. cit.) as conclusive for the course of
3 Credner, H., " Die Delten," Petermann Geog. Mitth., Erganzungs-
heft 56, pp. 1-74, pi. 3, 1878.
4 Grabau, A. W., Early Paleozoic Delta Deposits of North Amer-
ica," Bull. Geol. Soc. Am., vol. 24, pp. 399-528, 113.
B Barrell, J., idem., vol. 23, pp. 377-446, 1912.
22 Tuscaloosa Formation [220
the Tennessee River across Walden Ridge, I cannot help
believing that the Cretaceous ancestor of this stream at the
beginning of Tuscaloosa time, instead of making the sharp
turn to the northwest at Guntersville, Alabama, which it does
at present, continued southwestward down either Brown or
Big Spring valleys and reached the sea through either the
Mulberry or Locust fork of the Warrior River. This, how-
ever, is not an essential part of my argument for the delta
character of the Tuscaloosa formation, since there was obvi-
ously at that time a stream or a series of streams draining to
the southwest and engaged in removing the debris of the long
weathered land mass.
SW NE
POTTSVILLE
FIG. 2.
Section showing relation of the Tuscaloosa deposits to those of
the Eutaw and Selma formations.
I do not wish to be understood as ignoring the fact that
some of the Tuscaloosa deposits are sub-aerial and that ori-
ginally the delta deposits probably continued inland up the
valley or valleys for considerable distances as continental de-
posits of channels, flood plains and lakes. The antecedent
meanders of the present streams give clear evidence of con-
ditions that prevailed on the Cumberland peneplain that were
suitable for the formation of ox-bow lakes. There must have
been quiet waters in the delta itself in certain bayous or
possibly lakes like lakes Salvador, Ponchartrain and Borgne
of the present Mississippi delta region. Certainly the leaf-
bearing clays near Glen Allen and Shirley's Mill in Fayette
County, Alabama, were formed in such quiet bodies of water
with densely wooded shores.
The relations of the Tuscaloosa formation emphasizes its
delta character as is shown in the accompanying textngure.
221] E. W. Berry 23
The Tuscaloosa sands grade seaward into the glauconitic
sands and thinly laminated clays of the Eutaw formation
which contains a sparing representation of the marine life
of the time,, which must have been in part at least contem-
poraneous with the Tuscaloosa. A few plants in the near
shore transgressing phase have been collected from near
Havana in Hale County, Alabama. The upper Eutaw, or
Tombigbee sand member I regard as a transgressing deposit
and in conformity with this interpretation it contains a much
better marine fauna than the earlier Eutaw deposits. Over-
lying the Eutaw formation is the Selma chalk — an argilla-
ceous limestone or calcareous clay which reaches its maximum
thickness in the same region as does the Tuscaloosa sands,
namely southwest of the axis of the Appalachian land mass.
In this area the Selma chalk continues upward to the Eocene
contact. Its outcrop as shown on the accompanying sketch
map is almost perfectly lunate, and at its horns both to the
east and the north it passes over into sands. The Selma, as
shown by its abundance of Ostracea and other Mollusca is a
shallow water deposit. So far as my observation goes it is
entirely destitute of drift wood, lignite or any considerable
sandy beds in the area of its greatest thickness and the point
that I wish to make is that the southwestern drainage that
explains the character of the Tuscaloosa sediments must have
been reduced to a minimum or become practically non-exist-
ant before the deposition of the Selma chalk. The prevailing
direction of the drainage during Selma time must have been
to the southeast and northwest in order to explain the Eipley
sands in those regions and the absence of any except the
finest terrigenous materials in the main body of the Selma
chalk.
Inferentially if the Cretaceous Tennessee River was a fac-
tor in the building of the Tuscaloosa delta, local warping
must have broken its continuity with the Warrior drainage
and started it toward the northwest before the deposition of
the Selma chalk. It is possible that this may have been
accomplished without local warping by the simple clogging
24 Mineralizers in Ore Segregations [222
of its distributaries as a result of their own loads combined
with decreased run off. This set of factors combined with
the westward tilting that resulted in the Eipley Cretaceous
and Midway Eocene seas penetrating up the Mississippi val-
ley as far as southern Illinois is sufficient to account for the
observed change, of course assuming that there has been such
a change. This may be compared to the analogy of the shift-
ing of the present Mississippi delta to the eastward by marine
currents.
The remnants of heavy gravels of Tuscaloosa age that have
been traced by Wade across Tennessee and into Kentucky
appear to represent the gradual migration or shifting north-
ward of such a stream. That the western Highland Eim
of Tennessee is a middle or late Tertiary planation of pre-
vailingly siliceous rocks by the Tennessee River in its lower
northward course is probably true but hardly within the
scope of the present brief note.
THE ROLE OF MINERALIZERS IN ORE SEGREGATIONS
IN BASIC IGNEOUS ROCKS
By JOSEPH T. SINGEWALD, JR.
Though one of the latest groups of ore deposits to be defi-
nitely recognized, the magmatic segregations were firmly es-
tablished as one of the major types through the classic work
of J. H. L. Vogt twenty-five years ago ; and it has been gener-
ally felt by economic geologists that the mode of formation
of these deposits was so clearly understood that they consti-
tuted a group concerning the genesis of which there was no
further question. More thorough petrographic studies of
many examples of deposits classed with the magmatic segre-
gations and metallographic investigation of the ores, espe-
cially during the last decade, have accumulated more and more
evidence to show that mineralization was not so simple and
did not conform strictly to the conception of a magmatic
segregation in the sense in which that term is generally
223] J. T. Sing ew aid 25
thought of. The time has arrived for a definite recognition
of these discordant data and a remolding of our conceptions
in harmony with them.
The term magmatic segregation was borrowed by the eco-
nomic geologist from the petrographer and used in the petro-
graphic sense. Its application to the explanation of the
genesis of certain ore deposits seemed very plausible. It is
a matter of common petrographic knowledge that no large
body of igneous rock is of uniform composition and that
frequently the composition of a portion of the mass departs
widely from the average. Consequently there were forces at
work prior to or during the consolidation of the molten
magma which caused local segregations of certain of its con-
stituents. The nature of these forces has long been a matter
of discussion and speculation but unanimity of opinion has
not been attained and there is no thoroughly satisfactory
explanation of the process which is known as a magmatic
segregation or differentiation. The usual manifestation of
the phenomenon is in the local accumulation of the more basic
constituents of the magma.
The basis for the application of this process as an explana-
tion of ore genesis rests on certain other observations in the
field of petrography. There is present in almost all igneous
rocks a group of opaque minerals, occurring as accessory con-
stituents and with euhedral forms, the most common repre-
sentatives of which are the sulphides of iron, frequently cu-
priferous, and the oxides of iron, frequently chromiferous or
titaniferous. On account of their commonly euhedral forms,
these minerals are regarded by petrographers as the earliest
constituents of the magma to crystallize. Furthermore, these
minerals are concentrated together with the basic silicates in
the process of rock differentiation.
There are many ore deposits world-wide in their distribu-
tion possessing certain common characteristics, among which
may be mentioned: (1) the ore minerals consist of one or
more of the accessory opaque minerals common to igneous
rocks; (2) the enclosing rock is always an igneous rock and
26 Mineralizers in Ore Segregations [224
usually basic in composition; (3) the gangue minerals of
these deposits are the same as the constituent minerals of
the enclosing rock; (4) the* ore body frequently passes by
gradual transition into the igneous rock by a decrease in the
amount of the ore minerals and increase in the amount of
the silicates. These deposits appeared to be an integral part
of the igneous rock in which they are found and to represent
an extreme facies of the product of rock differentiation, and
consequently were established as an independent group of ore
deposits to which the name magmatic segregation was applied.
The group was subdivided by Vogt into three divisions ac-
cording as the metal occurs in the native, oxidic or sulphidic
form. Segregations of native metals as primary ore deposits
are of little economic importance, but the placers derived
from such of native platinum in the Urals are our principal
source of that metal. Segregations of oxidic ores are our
only source of chrome ores, include countless deposits of
titaniferous iron ores, and important deposits of non-titan-
iferous iron ores. Segregations of sulphidic ores include the
nickeliferous and supriferous pyrrhotites and probably a few
copper sulphide deposits.
The metallic content of the segregations of the native
metals is usually rather sparsely disseminated through the
rock, and on account of the few examples and their minor
importance, the propriety of regarding the metal as a segre-
gation and product of crystallization from a molten magma
has been little questioned. The segregations of oxidic ores
usually occur well within the igneous mass, and there are so
many admirable illustrations of gradation from ore-mineral
bearing rock to ore body that no particular significance has
been attached to the observation in a number of instances
that the ore minerals are later than the silicates, and the
conception of a segregation and solidification from a molten
magma has been rarely challenged. The position of the sul-
phidic deposits has, however, been somewhat dubious from
the start. They tend to occur on the periphery of the ig-
neous mass, the sulphides often penetrate into the wallrock,
225] J. T. Singewald 27
it was early recognized that in part at least the sulphides are
distinctly later than the rock-forming silicates, and the rock
itself has frequently undergone considerable alteration.
Many geologists have consequently insisted on .regarding
them as hydrothermal deposits. A most interesting feature
of the controversy over the genetic position of these sulphidic
ores has been that the largest and most important example,
the nickel deposits of Sudbury, Ontario, which has been cited
by the advocates of the magmatic origin as a typical illustra-
tion of that type, is one to which most serious objection has
been raised by those contending for a hydrothermal origin.
In view of the departures manifested by these deposits
from the conceptions based on purely petrographic pheno-
mena and concepts, it is interesting to see how the problem
has been handled in four of the leading recent textbooks on
ore deposits. The four selected are: R. Beck, Die Erzlager-
statten, 1909 (3rd edition) ; Beyschlag-Krusch-Vogt, Die
Lag erstdtten der nutzbaren Mineralien und Gesteine, 1910;
W. Lindgren, Mineral Deposits, 1913; L. DeLaunay, Giles
Mineraux et Metalliferes, 1913.
Beck, in denning magmatic segregations, says : " In many
instances there took place in the rock either before or during
solidification from the molten state a concentration of the
ores into irregular masses. ... In spite of the concentra-
tion into a limited space, the ores of such deposits remain,
what they as scattered particles in the rocks in question are,
namely accessory constituents." Commenting on Vogt's ob-
servation that in certain of the Swedish and Norwegian titani-
ferous iron ore deposits the silicates formed first and then
the titanif erous magnetite, he says, " these are departures
from the rule otherwise prevailing for eruptive rocks that the
iron ores belong to the earliest minerals to separate." In
all chrome deposits for which he cites the sequence of crys-
tallization, the chromite is the earliest constituent. Of the
sulphidic deposits, on the other hand he says, " The strict
proof of segregation from a molten magma cannot always be
established with the same degree of sharpness. . . . For a
28 Mineralizers in Ore Segregations [226
great many occurrences, which numerous authors consider a
direct segregation from eruptive rocks, one must at least con-
sider probable a later secondary recrystallization of the ores
by aqueous processes which brought about a partial migration
and an impregnation of the wallrock." These conclusions
are based largely on his own work in 1902 and 1903 on the
deposits of nickeliferous pyrrhotite and chalcopyrite at Soh-
land in Saxony, where he found ore deposition took place by
replacement subsequent to the hydrothermal alteration of the
rock, though he believes both followed immediately after its
solidification.
"With the exception of the treatment of the sulphidic ores,
the position of Beyschlag, Krusch and Vogt is similar to that
taken by Beck. Their ideas are of course largely those devel-
oped by Vogt. Their conception of the genesis of these ore
deposits is that, " In the same manner in which larger masses
of mica and feldspar can collect out of a granite magma,
segregation of ores can take place, as for example of mag-
netite, titaniferous magnetite, chromite and pyrrhotite, in
such igneous rocks which normally carry these ores as acces-
sory constituents." They call attention to the fact that the
ore minerals followed by the iron-magnesium silicates are
the earliest constituents to crystallize in most eruptive rocks
and they are also the constituents that migrate in magmatic
differentiation. Magmatic segregation is distinguished from
ore deposition in which mineralizers participate as follows:
" The genetic difference consists essentially therein that the
magmatic segregations result from a single differentiation
process of the magma, whereas in the case of the pneumato-
lytic and contact metamorphic deposits the metallic content
originally belonging to the magma is transferred to an aque-
ous or gaseous solution and later deposited from this through
new processes." Though in most cases the two groups are
considered as sharply differentiated, they admit that occa-
sionally there are intermediate stages in which magmatic dif-
ferentiation is accompanied by pneumatblytic or pneumato-
hydatogenetic processes. They definitely state that the chrome
227] J. T. Singewald 29
ores crystallized out of a magma and that the forma-
tion of the titanif erous magnetites " depends on a pure mag-
matic separation, not accompanied by special pneumatolytic
processes," and that the process differs from ordinary rock
differentiation only in that it has proceeded much further.
The characteristic association of more or less titanomagnetite
with the sulphides is taken to indicate a genesis for the latter
ores analogous to that of the titaniferous magnetites. In
further substantiation of the magmatic origin of the sul-
phides is the statement that secondary alterations such as
uralitization before ore deposition or contemporaneous with
it has not in general occurred. They emphasize the fluidity
of the molten sulphides and the consequent power of pene-
tration into minute crevices and cracks and have proposed a
subdivision of injected sulphide deposits, which represents
intrusions of molten sulphides into the country rock. In
such an interpretation of a number of the most important
examples included under this subdivision, however, they stand
almost alone.'
The deposits under discussion are classed by Lindgren as
" Mineral deposits^Jefmed by concentration in molten mag-
mas," concerning which he says : " Certain kinds of mineral
deposits form integral parts of igneous rock masses and per-
mit the inference that they have originated, in their present
form, by processes of differentiation and cooling in molten
magmas/' Of the oxidic ores he says chromite appears in all
cases to be the earliest consolidated constituent, but that the
titaniferous iron ores have as a rule crystallized after the
silicates ; but he says further about the latter : " Petrographic
research has long ago shown that ilmenite with magnetite is
one of the earlier products of consolidation in magmas and
is contained in almost all diabases, basalts, and gabbros. . . .
The larger masses of ilmenite are simply facies of the rock
itself produced by concentration from the same magma."
Lindgren's position concerning the sulphides is almost identi-
cal with that of Beyschlag, Krusch and Vogt, as is evidenced
by such statements as, " Some of the magmatic sulphide
30 Mineralizers in Ore Segregations [228
deposits are simple basic rocks abnormal in containing much
pyrrhotite, chaicopyrite and pentlandite," and, " Some de-
posits in which the ore consists mainly of solid pyritic
minerals present features which can hardly be explained
otherwise .than by actual injection of molten sulphides," in
spite of his admission that " on the whole the sulphides are
the latest products crystallized." In reply to the advocates
of a hydrothermal origin for certain of these deposits, % he
charges them with having confused secondary changes with
primary deposition.
DeLaunay's treatment of these deposits differs consider-
ably from any of the preceding. The first five divisions of
his genetic classification of ore deposits are the following:
1. Gites d'Inclusions.
2. Gites de Segregation.
3. Gites de Depart Immediat ou de Segregation Peri-
pherique Sulfuree.
4. Gites de Contact du Type Banat.
5. Impregnations Diffuses de Profundeur (includes amas
pyriteux) .
" Deposits of inclusions are those where a useful mineral
occurs in an igneous rock in the same relation as the other
constituent elements." This division is of theoretic rather
than practical importance, and includes only native metals
and oxides present as normal accessory constituents of an
igneous rock without the intervention of mineralizers. The
segregation deposits, he says, might be regarded as having
been effected without intervention of volatile constituents,
nevertheless the general opinion today is that water and pro-
bably other mineralizers have played a role, though he con-
siders them formed in a medium poor in mineralizers. The
ores are native metals and oxides. The Gites de Depart
Immediat, or peripheral sulphide seregations, he says, have
usually been considered examples of true segregations which
differ from the internal oxidic segregations by their position
and nature. DeLaunay believes it necessary, however, to
229] J. T. Singeiuald 31
separate them entirely from the true segregations, for there
has been a concentration of sulphides not only in the rock
but at its contact, and they appear to him to be a close
parent to contact metamorphic deposits which are formed
when the wallrock is a limestone. They represent a type of
ore deposition in which mineralizers are more abundant and
active than in the preceding. The very close relation postu-
lated between these deposits and typical contact metamorphic
deposits indicates clearly that he does not look upon them
as representing a crystallization from a molten state. The
mineralization of the last group is analogous to that of the
fourth, the types of deposits included under it being formed
where the country rock is other than a carbonate rock. It
includes most of the deposits classified by Beyschlag, Krusch
and Vogt as injected sulphide deposits. There are no sharp
lines of demarcation between these groups, as DeLaunay
recognizes a complete transition from purely igneous deposits
to hydrothermal veins and that in some instances it is difficult
to decide between fusion and solution.
In an attempt to settle some of the doubtful points con-
cerning the mode of formation of the sulphidic ores usually
classed as magmatic segregations, C. F. Tolman, Jr. and A.
F. Eogers of Stanford University have just published the
results of a very comprehensive petrographic and metallo-
graphic investigation of those ores as a monograph entitled
" A Study of the Magmatic Sulfid Ores." They formulate a
number of statements which they find applicable to all of the
deposits studied, the most significant of which are :
1. The first minerals to form are olivine, the pyroxenes
and the feldspars.
2. Magmatic alteration of the silicates often takes place
prior to the formation of the ore minerals. The most com-
mon change is that of pyroxene to hornblende, but easily
distinguishable from the hydrothermal process of uralitiza-
tion.
3. The ores replace the silicate minerals but without re-
action rims.
32 Mineralizers in Ore Segregations [230
4. The ores are introduced one after another in the fol-
lowing invariable sequence: (1) magnetite and ilmenite, (2)
pyrrhotite, (3) pentlandite, (4) chalcopyrite. There is a
certain amount of replacement of the earlier ore minerals by
the later ones.
5. Hydrothermar alteration is distinctly later than the
period of ore deposition.
These data of observation lead them to a theory of genesis
more nearly analogous to that of DeLaunay than any of the
others mentioned above. The fact that the ore minerals
replace the silicates without the formation of metallic sili-
cates by reaction is interpreted to mean that the ores were
not introduced in a molten state but that the same agency
that brought in the sulphides removed the dissolved silicates,
indicating the presence of active mineralizers. The altera-
tion of pyroxene to hornblende is further evidence of the
presence of mineralizers. Consequently they conclude that
mineralization took place at a temperature below the melting
point of the ores and that they were held in solution through
the agency of mineralizers. On the other hand, that ore de-
position took place under conditions different from those of
non-magmatic high temperature deposits is shown by the
absence of the secondary silicates characteristic of ordinary
pneumatolytic and hydrothermal processes, or that where
present they belong to a distinctly later period. They con-
clude, that the magmatic ores "have been introduced at a
late magmatic stage as a result of mineralizers."
The direct evidence presented by Tolman and Eogers is
derived from the sulphide deposits, but the presence of a
greater or less quantity of titaniferous magnetite in these, and
numerous references in • the literature to the silicates pre-
ceding the ores in order of crystallization in deposits of titan-
iferous magnetite, led them to infer that the same observa-
tions and same conclusions apply equally well to the oxidic
ores. My own experience with the titaniferous magnetites
corroborates the correctness of this inference. The relations
between ore minerals and silicates figured and described for the
231] J. T, Singewald 33
sulphide ores are repeatedly duplicated in thin sections and
polished sections from all occurrences of titaniferous iron
ores in the United States. Titaniferous magnetite later than
the silicates and replacing them is seen in nearly every section
of the ores, though many of the contacts of the two sets of
minerals show what L. C. Graton and D. H. McLaughlin
have recently termed mutual boundaries, that is, boundaries
that give little evidence of the sequence of the minerals.
Only rarely is there unmistakable evidence of primary sili-
cates distinctly later than the ore. The replacement of the
silicates by the ore has not been accompanied by the forma-
tion of reaction silicates and in several instances hornblendi-
zatioirhas preceded the deposition of ore, phenomena in har-
mony with the nature of mineralization in the case of the
sulphide ores. If segregation takes place without the interven-
tion of mineralizers, one might expect the deposit at Iron
Mountain, Wyoming, to afford such an example. The ore
body there occurs as an almost pure mass of titaniferous
magnetite .cutting the anorthositic country rock as sharply
as any igneous dike ever pictured. Yet the numerous oliviny
crystals which occur locally in the ore are rounded and em-
bayed without the formation of reaction silicates in exactly
the same manner as in other occurrences. The deposit sug-
gests an injection from a basic magma analogous to a peg-
matite from a more acidic. In other cases, particularly at
Grape Creek, Colorado, the introduction of ore has been
accompanied by alteration of the feldspar so that the mag-
netite is separated from it by a band of hornblende, indi-
cating greater than usual activity of mineralizers. The Min-
nesota deposits conform for the most part to the general rule
that the ore is later than the silicates and afford some exam-
ples of hornblendization preceding or contemporaneous with
ore deposition, but also instances of feldspar and pyroxene
later than ore.
An excellent example of an iron ore deposit in a basic
igneous rock giving unmistakable evidence of active partici-
pation by mineralizers in the formation of the ore is afforded
3
34 Mineralizers in Ore Segregations [232
by. the Tofo deposit north of Coquimbo, Chile, being worked
by the Bethlehem Steel Company. This consists of a large
mass of comparatively pure magnetite forming the top of a
hill on the east side of the coast range and occurring within a
large area of gabbro rock. The igneous mass has undergone
considerable differentiation and various rock types are repre-
sented in the vicinity of the ore body from highly feldspathic
to almost pure ferromagnesian silicate rocks, some of which
occur as dikes. The broader relations of the ore body are
such as to suggest at once a magmatic segregation; but, at
the same time, there are many features that suggest pneuma-
tolysis. Adjacent to the ore, there are numerous stringers of
magnetite in the country rock, many of them of no greater
thickness than a knife blade, which traverse it in such a
way as to preclude the entrance of molten oxides and that can
be explained only on the basis of the high liquidity at lower
temperature that would be imparted by the presence of
abundant mineralizers.
The argument for the participation of mineralizers in the
formation of magmatic deposits is a plausible one ,also from
a general standpoint of ore genesis. Processes in nature
representing different stages of a sequence from a given
starting point are not usually separated by a hiatus. It is
generally accepted today that igneous magmas are the pri-
mary sources of the metals and modern genetic classifications
group ore deposits according to their position or relation to
the original sources. It has been customary, however, to-
draw a sharp line between one group of deposits which it was
held segregated from the molten magma and solidified with
it, and such groups as represented deposition of material
extracted from the magma by mineralizers and constituting
the pneumatolytic and hydrothermal deposits. DeLaunay's
classification recognizes no such hiatus in the sequences of
mineralization, but postulates a gradually increasing partici-
pation of mineralizers and hence a gradual gradation from
one stage to the next. It goes even a step further and indi-
233] J. T. Singewald 35
cates that concentration of the metallic content of a magma
to the extent necessary to form important ore bodies takes
place only when the necessary migration of the metals is
aided by the presence of mineralizers. Eor the only group
recognized by him in which mineralizers did not participate
in ore deposition, his gites d' inclusions, contain no deposits
of economic importance; and it is only in his next group,
in which mineralizers begin to play a part, that important
ore deposits begin to be represented. There have been two
lines of thought seeking to explain ore genesis, the one repre-
sented by the French school which has always emphasized
the role of mineralizers, and the other by the American and
German economic geologists who have tended to draw the
sharp line of demarcation between the magmatic deposits and
the non-magmatic. The participation of the latter group has
so greatly preponderated over that of the former during the
last quarter century in the development of the science of
economic geology that the views of the French school have
often been completely overshadowed and have not received
the attention they merit. The monograph by Tolman and
Rogers will serve to establish among American economic geol-
ogists the ideas embodied in the conceptions of the French
school. It is hoped that this survey of the problem and the
corroborative evidence contributed in the case of the iron
ores will serve the same purpose. One cannot help but feel
that a new study of the chrome ores with this interpretation in
mind would place them in harmony with it. As their case
now stands, they seem to be an exception and to represent a
direct segregation as the first product of crystallization from
a molten magma.
36 Environment of Tertiary Marine Faunas [234
THE ENVIRONMENT OF THE TERTIARY MARINE
FAUNAS OF THE ATLANTIC COASTAL PLAIN
By JULIA A. GARDNER
The Miocene and Pliocene deposits of the Atlantic Coastal
Plain have now been mapped in detail from New Jersey to
North Carolina and the 'contained faunas, which are prolific
and varied, have been rather fully described.1
The following formations have been recognized in the
Middle Atlantic region :
Maryland Virginia North Carolina
Pliocene : "Waccamaw
Yorktown Yorktown-Duplin
, St. Mary's St. Mary's St. Mary's
Miocene: J \ J J
Cnoptank
Calvert Calvert
All of these formations contain extensive molluscan faunas
and very large collections have been available for study and
comparison. An idea of the richness of these faunas may
be obtained from the following census of the faunas of the
respective formations :
No. of species in genera
Waccamaw 325-335 130
Yorktown 364-378 143
Duplin 420-431 154
St. Mary's 326-344 129
Calvert . 80-83 50
1 The more recent literature includes the following :
Whitfield, R. P., Hon. U. 8. Geol. Survey, vol. xxiv, 1894.
Clark, Martin, Glenn and others, Miocene vol., Md. Geol. Survey,
1904.
Gardner, J. A., "The Miocene and Pliocene Faunas of Virginia
and North Carolina," Prof. Paper U. S. Geological Survey.
(In press.)
235] J. A. Gardner 37
These faunas are exceedingly interesting, not only because
of their diversity and the remarkable 'development of certain
groups, but also because of the light they shed on the physical
conditions under which they lived. In the following notes,
which are based on the study of compiled tables of both recent
and fossil forms, an attempt is made to summarize the proba-
ble physical conditions indicated by this study.
Any attempt to reconstruct bottom conditions in the ancient
seas must of necessity be based upon data so meagre and so
inaccurate that any hope of obtaining absolute values is vain,
and yet it does' seem worth while to occasionally gather the
imperfect knowledge available and to try to interpret it.
Errors do, to a certain extent, neutralize one another and
within certain limits general tendencies and relative values
can be given with a very considerable degree of assurance.
Over 800 species have been determined from the Miocene
and Pliocene of Virginia and North Carolina and of these
approximately 20 per cent, persist into the recent faunas.
Certainly a number so large as this ought to give a fairly true
line upon general temperature and bathymetric conditions in
the middle and later Tertiaries.
It may be well to consider the main sources of error before
giving the conclusions which they modify.
A. SOURCES OF ERROR IN THE DATA UPON THE TERTIARY
FAUNAS.
1. Errors in determination.
This is one of the least important. The greater part of
the work upon the faunas in question has been done by less
than half a dozen students and the same collections, for the
most part, have been used for reference. Consequently the
determinations, whether accurate or inaccurate, are fairly con-
sistent. Furthermore, if two forms are so much alike that
there is a question as to their identity, a similarity of envir-
onmental conditions is implied, even though the differences
may later prove to be specific.
38 Environment of Tertiary Marine Faunas [236
2. A mechanical sorting of the shells.
This is a much more serious error and one which it is im-
possible to eliminate. One of the most interesting phases
of in-shore marine life is the dissimilarity in the dredge hauls
within a limited area. The in-shore currents are quite suffi-
cient to materially affect the character of the bottom and the
distribution of the algal growth and thus to limit the range
of a considerable number of species, particularly the vege-
table feeders. Unfortunately, almost all such ecologic varia-
tions have been washed away. Not only have near-by but
distinct assemblages due to slight differences in environmental
conditions been commingled but dead shells have been washed
down from the river mouths and up from the off-shores and
mixed together in a heterogeneous ensemble. The hard parts
of the smaller species, many of which constitute an important
item in the diet of various fishes may be carried for indefinite
distances beyond their normal habitat before being laid down
in their final resting place. In recent faunas extra-limital
shells are usually so badly worn that their distant origin may
be surmised but in the fossil forms it is much more difficult
to isolate them by this method. It is, however, reasonable to
suppose that forms occurring in any considerable abundance
are indigenous to the fauna but inferences made from the
presence of only one or two individuals should be guarded.
B. SOURCES or ERROR IN THE DATA UPON THE EECENT
FAUNAS.
1. Errors in determination.
These are much more frequent in the Recent collections
than in the fossil because the work has extended over a much
greater time and the personal element is much more conspicu-
ous. However, errors in the determination of the fossils are
frequently parallel to those of the Recent faunas so that the
final results are not always affected. The tendency in the
Recent work is towards an increasingly finer distinction of
species so that the ranges are becoming more and more re-
237] J* A. Gardner 39
stricted. This is especially true in certain families. In a
recent zoogeographic study of the West Coast Pyrammidelli-
dae 10 faunal zones were differentiated.2 The three most
populous were the Oregonic with 70 species, the Californic
with 164 and the Mazatlanic with 75. However, only 11
species common to the Oregonic and Californic were recog-
nized and only 2 common to the Californic and Mazatlanic.
No refined study such as this has ever been made upon any
of the East Coast molluscs, but when it is done the number
of species will doubtless be greatly increased and their ranges
greatly diminished. The fossil forms can then be interpreted
in terms of the Eecent with an accuracy and a detail far in
advance of anything that is possible at present. The knowl-
edge of the Tertiary ecology may approximate the Recent
but it can never go beyond it.
2. The limited number of dredging records.
Not only are the stations relatively few in number but
they are so grouped that there are long stretches which have
not yet been touched. The attempt has been made, however,
to cover the critical areas, such as that of the Florida coast,
Hatteras and Woods Hole. The New England fauna is well
known in a general way and extensive collections have been
made through the 'Gulf and the West Indies by the Blake
and the Albatross. A very short but significant report is that
of Bartsch and Henderson upon a two days' collecting trip
off Chincoteague Island on the Virginia coast for the pur-
pose of determining the extent of overlap of the southern
fauna.3 The latest of the larger reports, that upon the
Woods Hole region is by far the most satisfactory excepting
that it covers an area so restricted and so little diversified.
The arrangement, however, is excellent for an ecologic study,
the dead shells are isolated from the living and the young
2 Bartsch, P., 1912, Proc. u. S. National Museum, vol. 42, p. 299.
3 Bartsch and Henderson, 1914, Proc. U. 8. Nat. Mus., vol. 47, pp.
411-421.
40 Environment of Tertiary Marine Faunas [238
from the adult, the number of specimens is given and the data
upon depth, temperature, salinity, etc., is complete and accu-
rate. The bathymetric distribution of most of the southern
stations is unfortunate for those interested in determining
the limits in depth of the littoral fauna. Very little shore
dredging has been done and there are very few records from
less than 10 fathoms. A number of unusually rich hauls were
made off Hatteras between 15 and 25 fathoms. The 49 and
63 fathom stations include in addition to the native fauna a
considerable number of young or more or less worn shells
referrable to the more abundant species in the lesser depths
but in the great majority of records these fortuitous shells
have not been isolated. However, the general relationships
which come out of an interpretation of the recent elements in
the fossils faunas are probably true, even though the data
upon which the results are based is woefully inadequate.
Five formations have been recognized in the Miocene and
Pliocene of Virginia and North Carolina, — the Calvert, St.
Mary's and Yorktown in Virginia and the Yorktown, Duplin
and Waccamaw in North Carolina. The Yorktown and Du-
plin were probably, for the most part, synchronous though
laid down in separate basins. Approximately 65% of the
species common to the Calvert and Recent faunas have been
reported from north of Hatteras, the limit of range of many
of the northern and of the southern forms; 54% of the St.
Mary's; 46% of the Yorktown; 35% of the Duplin, and
36% of the Waccamaw. Factors other than temperature have
modified somewhat the figures for the Duplin and Waccamaw,
for there is no reason to suppose that the Waccamaw sea was
not quite as warm as the Duplin.
The break between the late Oligocene and the early Mio-
cene in the Southern Atlantic states is one of the sharpest in
the stratigraphic succession of the Cenozoic. The Oligocene
has not been recognized either in Virginia or North Caro-
lina but the early Miocene fauna is similar in general charac-
ter wherever it occurs along the East Coast. Twenty species
239] J. A. Gardner 41
from the Calvert of Virginia, approximately 12l/2% of the
entire fauna, persist into the Eecent and furnish consistent
evidence of environmental conditions during Calvert Times.
The depth of the waters in which they live did not, in all
probability, exceed 20 or 25 fathoms. The temperature was
perceptibly lower than that of any other of the middle or
late Tertiary faunas of that region. The bottom was prob-
ably soft, dominaritly mud,, with a mixture of sand. At
least a portion of the shore must have been sufficiently shel-
tered to encourage the growth of kelp and ,sea lettuce and
other sea weeds to which many of the smaller univalves and
bivalves characteristically attach themselves. The Calvert
of Maryland is unusually varied for the latitude. It is quite
possible that the ancient shore line in that area was fringed
with islands and sand spits similar to those along the outer
margin of Virginia and North Carolina today and that dur-
ing Calvert times the spits were now washed away, admitting
the off-shore fauna, and now built up, protecting the waters
behind them and allowing a warmer water element to creep
in and establish itself.
There is no evidence of any marked change in the ecology
in passing from the Calvert to the St. Mary's. All of the
recent species represented in the Calvert are present in the
St. Mary's but the number is almost tripled. The northern
element, however, is slightly less prominent and the southern
element a little more so. The fauna is prolific in individuals
but not greatly diversified. The outstanding differences be-
tween the St. Mary's molluscs of Maryland and those of
Virginia and North Carolina are mainly those of latitude,
although the presence in Maryland of a considerable number
of Surculas, one of the characteristically deep-water pleuroto-
mids suggests deeper water in that area. The faunas in Vir-
ginia and North Carolina are remarkably uniform. There
are, to be sure, a few species common to Maryland and
northern Virginia which are not found in North Carolina
and a few of southern affinities which are restricted to North
Carolina. The monotony of the assemblage indicates a long
42 Environment of Tertiary Marine Faunas [240
stretch of open shore with only an occasional bight from the
vicinity of the present York River in Virginia to that of
the Neuse River in North Carolina. The slope of the conti-
nental shelf must have been very gentle, not more than 3' to
the mile, since there is no perceptible change in the bathy-
metric character of the fauna between the extreme eastern
and western outcrops, a distance of 60 or 70 miles. There
is no reason to believe that any part of this platform was
submerged to a depth of more than 30 or 40 fathoms. The
bottom was doubtless soft and, for the most part, muddy
since the mud-burrowers, notably Mulinia are exceedingly
prolific and widely distributed. The waters must have been
sufficiently clear, however, and the bottom sufficiently shelly
to furnish clutch for the numerous oyster spat and to permit
them to mature. Conditions were probably not very favor-
able to algal growth, since most of the groups which charac-
teristically attach themselves to the sea-weeds of various
kinds have a meagre representation.
The elevation along the Hatteras axis at the close of the
St. Mary's was apparently great enough to cut off the York-
town basin in Virginia from the Duplin in southern North
Carolina. The faunas of the two basins, though similar in
general character, differ more in detail than one would expect
in two shallow water faunas only a couple of hundred miles
apart. The contemporaneity of the Yorktown and Duplin
faunas was suggested by 'Dr. Dall more than fifteen years ago
and even at that time he brought forward in explanantion of
the conspicuous faunal differences the potency of the ocean
currents, a factor which has been so emphasized of late in the
distributional studies upon the West Coast. The Yorktown
fauna is strikingly like that listed by Bartsch and Henderson
from Chincoteague Bay, Accomac County, Virginia. The
greatest break in the East Coast life from the late Tertiary on
to the Recent comes at Hatteras, the point at which the Gulf
stream leaves the inshore and swings out toward the open
sea. Many of the sub-tropical species are able to follow along
the shore as far as it is protected by the warm current, which
241] /. A. Gardner 43
also serves as an effective barrier to most of the northern
forms. At Chincoteague, Bartsch and Henderson found that
while along the ocean side of Chincoteague Island the
fauna was consistently northern in its affinities, in the pro-
tected inner bight there was an overlap of the southern
faunas. Twenty-eight of the 70 species which they have listed
are present in the Yorktown fauna and the number of com-
mon forms will doubtless be greatly increased with further
investigations. The ensemble of the fossil and Eecent faunas
is conspicuously similar although the southern element is
a little stronger in the former. However, much the same
conditions of sandy shores and muddy bogs more or less
choked with algal growth obtained in the Yorktown as along
the Virginia coast today. The fauna, like those that precede
and those that follow it, is characteristically shallow water
and it is doubtful if any of the indigenous species lived at
a depth of more than 25 fathoms.
The Duplin fauna is less homogeneous. Mingled with the
large pleurotomid element and a considerable number of
volutoids, one of the most uniformly deep-water families,
are nine species of Ilyanassa, a group that is known to occur
only along inter-tidal beaches. The sediments of the Duplin
are, for the most part, coarse sands. It seems on the whole
reasonable to suppose that the native Duplin fauna lived near
the mouth of some rather large estuary and that the streams
entering the bay brought down in considerable numbers the
beach-dwellers from farther up shore, while strong currents
from the south sweeping along the mouth of the estuary
contributed not only a southern element of living forms but
also a large number of dead shells referrable to extra-limital
species. One hundred and thirteen Duplin species are either
identical with the Recent forms or so closely allied that they
have been confused in the synonymies. Of this number 97,
approximately 85%, occur between Hatteras and Florida. Of
the remaining 18 only a single species, the rather uncommon
Polynices heros, does not range as far south as Hatteras.
Most of the characteristic Florida elements, however, are
4:4 Pelecypods of the Boiuden Fauna [212
absent, so that it seems probable that Duplin temperature
conditions are more nearly duplicated between Cape Fear
and Charleston, South Carolina, than along any other sec-
tion of the Coast.
In the succeeding Waccamaw the conditions of the Duplin
were some of them intensified but not materially changed.
The fauna is, on the whole, more consistent, for both the
brackish and the deep water elements are rather less pro-
nounced. There were, judging by the abundance of such
forms as the. Olivas and Olivellas, extensive sand flats covered
by from 2 to 10 fathoms of water, while the wealth of
Bittiums and small Cerites and other groups of similar habits
demands conditions favorable for extensive algal growth.
There is a curious similarity in the general make-up of the
Waccamaw and Yorktown faunas, due, doubtless to the
similarity in ecology. The Waccamaw waters, however, were
decidedly warmer than those of the Yorktown, in fact they
were in all probability warmer than at any other period during
the middle or late Tertiaries or than those off North Carolina
today. The evolution toward the Recent Cape Fear fauna
has been marked less by the introduction of a northern
element than by the restriction of the more sensitive southern
forms to the Floridian province.
THE PELECYPODS OF THE BOWDEN FAUNA
By WENDELL P. WOODRING
1. INTRODUCTION
The marls exposed along the coast between Morant Bay and
Port Morant, near Bowden, almost at the southeastern ex-
tremity of the island of Jamaica, have long been known to
contain a prolific and splendidly preserved molluscan fauna.
In 1862 Mr. Lucas Barrett, the Director of the Jamaican
Survey, deposited in the British Museum a collection ap-
parently from this locality. A year later Mr. Carrick T.
243] W. P. Woodring 45
Moore 2 submitted a brief report on the mollusca. The first
systematic account of the fauna was published in 1866 by
the late Mr. E. J. Lechmere Guppy,3 who later made several
additional contributions.4 Mr. Eobert Etheridge 5 in an ap-
pendix to the report of the Jamaican Survey, published in
1869,, discussed the general aspect of the fauna. In 1896
Guppy and Ball6 issued descriptions of a number of new
species. The report of Mr. Eobert T. Hill 7 on his recon-
naissance of Jamaica contained a brief notice of the mollus-
can elements of the fauna. In the Wagner Institute Papers
Dr. Dall 8 described many new species and noted the occur-
ence of previously described forms; in addition, the last
fascicle contained a discussion of the correlation of the fauna
and a check-list.9
2. BIOLOGICAL CHARACTER OF THE FAUNA
The present study has resulted in the recognition of be-
tween 190 and 200 species of pelecypods, of which almost
half are new. These are segregated into 64 genera and 40
families. The superspecific groups and the number of
species in each group are given in the following list:
2 Moore, C. T., Quart. Jour. Geol. 800., London, vol. 19, pp. 510-513,
1863.
3 Guppy, R. J. L., Quart. Jour. Geol. Soc., London, vol. 22, pp. 281-
295, 1866.
4 Guppy, R. J. L., Geol. Mag., decade v, vol. 4, pp. 496-501, 1867:
idem, decade 2, vol. 1, pp. 404-411; 436-446, 1874; idem, vol. 2, pp.
41-42, 1875; Proc. Assoc. Trinidad.
5 Etheridge, R., Reports on the Geology of Jamaica, Part 2, West
Indian Survey, Mem. Geol. Survey Great Britain, ap. 5, pp. 319-329,
1869.
6 Guppy, R. J. L., and Dall, W. H., Proc. U. S. Nat. Mus., vol. 19,
no. 1110, pp. 303-331, 1896.
7 Hill, R. T., Bull. Mus. Compt. ZooL, Harvard, vol. 34 (geol. ser.
4), pp. 145-152, 1899.
8 Dall, W. H., Trans. Wagner Free Inst. fifci., Philadelphia, vol. 3,
pts. 1-6, 1890-1903.
9 Idem., pt. 6, pp. 1580-1588, 1903.
4:6 Pelecypods of the Bowden Fauna [24-i
Nucula 2 pp.
Leda 7 spp.
Yoldia 1 spp.
Tindaria 1 spp.
Limopsis 2 spp.
Area (Area s. s.) 4 spp.
Barbatta (Acar) 2 spp.
(Calloarca) 4 spp.
(new section) 3 spp.
(Fossularca) 2 spp.
Scapharca (Scapharca s. s.) 9 spp.
(Argina) 1 sp.
(Cunearca) 1 sp.
(Bathyarca) 1 sp.
(Anadara) 1 sp.
Glycymeris 3 spp.
Pinna 1 sp.
Atrina 1 sp.
Melina 1 sp.
Pteria 1 sp.
Ostrea 3 spp.
Pecten
Pecten (Pecten s. s.) 1 sp.
(Euvola) 2 spp.
Chlamys (Chlamys s. s.) 4 spp.
(Aequipecten) 5 spp.
Pseudamusium ( Pseudamusium s. s.) 1 sp.
Amusium (Amusium s. s.) 1 sp.
(Propeamusium) 1 sp.
Spondylus 3 spp.
Plica tula 1 sp.
Lima (Lima s. s.) 1 sp.
Lima (Mantellum) 1 sp.
Limaea 1 sp.
Placuanomia 1 sp
Anomia 2 spp.
Modiolus (Brachydontes) 1 sp.
Dreissena 1 sp.
Julia 1 sp.
Verticordia (Trigonulina) 1 sp.
(Haliris) 1 sp.
Poromya 1 sp.
Cuspidaria (Cardiomya) 1 sp.
(Bowdenia) 1 sp.
Crassatellites (Crassatellites s. s.) 2 spp.
(Crassinella) 3 spp.
Venericardia (Venericardia s. s.) 1 sp.
(Pteromeris) 1 sp.
Chama 2 spp.
Echinochama 1 sp.
Codakia (Codakia s. s.) 2 spp.
(Jagonia) 3 spp.
Myrtaea (Myrtsea s. s.) s spp.
(Eulopia) 3 spp.
Phacoides (Phacoides s. s.) 1 spp.
Here (Here s. s.) 4 spp.
(Pleurolucina) 1 sp.
(Cavilucina) 1 sp.
245] W. P. Woodring 47
Pseudomiltha 1 sp.
Callucina 3 spp.
Parvilucina (Parvilucina s. s.) 3 spp.
(Bellucina) 2 spp.
Divaricella 2 spp.
Diplodonta (Diplodonta s. s.) 2 spp.
(Pelaniella) 1 sp.
(Phlyctiderma) 1 sp.
Erycina 2 spp.
Anisodonta (Basterotia) 1 sp.
Montacuta? 1 sp.
Cardium (Cardium s. s.) 1 sp.
Trachycardium 4 spp.
Fragum (Fragum s. s.) 2 spp.
(Trigoniocardia) 3 spp.
Laevicardium 1 sp.
Protocardia 2 spp.
Transennella 2 'spp.
Tivela 1 sp.
Gafrarium (Gouldia) 1 sp.
Pitaria (Hyphantosoma) 1 sp.
(Lamelliconcha) 1 sp.
Antigona (Ventricola) 1 sp.
Cyclinella 1 sp.
Chione (Chione s. s.) 3 spp.
Chione (Lirophora) 1 sp.
Parastarte 1 sp.
Cooperella (new section) 1 sp.
Tellina
Arcopagia (Merisca) 4 spp.
(Phyllodina) 2 spp.
(Eurytellina) 1 sp.
Moerella 2 spp.
Angulus (Angulus s. s.) 5 spp.
(Scissula) 1 sp.
Strigilla 1 sp.
Macoma
Psammacoma (Psammacoma s. s.) 2 spp.
Cymatoica 1 sp.
Semele (Semele s. s.) 1 sp.
Abra 2 spp.
Donax 2 spp.
Psammosolen 1 sp.
Spisula 1 sp.
Ervilia 1 sp.
Corbula (Aloidis) 1 sp.
(Cuneocorbula) 1 sp.
(Bothrocorbula) 1 sp.
Gastrochaena 1 sp.
Martesia? 1 sp.
Xylophaga? 1 sp.
Teredina 1 sp.
Teredo 1 sp.10
10
An additional form is considered the type of a new genus of
doubtful affinities placed provisionally among the Isocardiacea, prob-
ably near the Vesicomyacidas.
48 Pelecypods of the Bowden Fauna [246
The Prionodesmacea play an important role in the constitu-
tion, being represented by 79 species, or more than 40 per
cent of the fauna. The larger part of this number is contri-
buted by -the taxodonts, which include 44 species. The most
abundant taxodont is the genus Area, which has 28 species
distributed among 10 sections. The Scapharcas are the most
prolific, both individually and specifically. The section
Cunearca, which usually occupies a position of importance in
the mid-Tertiary faunas of the Antillean region and its peri-
meters, is represented by a single small form and the sub-
genus Noetia is entirely absent. Three species of Barbatia
are grouped in a new section that bears a relation to Barbatia
s. s. similar to the relation between Argina and Scapharca
s. s. Another Barbatia of unusual type has been provisionally
referred to Fossularca, although it probably represents a new
section. A minute Bathyarca is abundant in one of the col-
lections, but is rather rare in the other minute collections
available.
Among the prionodonts the Pectens are subordinate only
to the Areas. They contribute 15 species representing seven
sections among which are included virtually all the groups of
a typical tropical fauna. The Aequipectens are the most
abundant and include several species that are widely distri-
buted in the Tertiary deposits of the Antillean region. With
regard to specific diversification Chlamys s. s. is comparable
to Aequipecten, but only one of the species is abundant. The
valves of a small delicate Pseudamusium s. s. are numerous
and the section Propeamusium is represented by a single
valve.
The oysters form a puzzling assemblage. In all the collec-
tions the number of individuals is small and large forms are
notably absent. The small size is probably not without sig-
nificance when it is considered that one of the Bowden species
reaches an imposing size in the Alum Bluff faunas and especi-
ally in the Santo Domingan fauna. A similar relation
obtains for an unusually large and ponderous Santo Do-
mingan Spondylus. If the current synonymy for Ostrea
247] W. P. Woodring 49
megodon Hanley is accepted, this species furnishes an example
of a former distribution on both sides of the Isthmus of
Panama and a present restriction to the Pacific side. Another
oyster probably is identical with the Eecent mangrove-
oyster, 0. folium Linnaeus. Although the species may not be
genetically valid, it may be assumed that the Bowden form
had the peculiar habits of the oyster that is frequently found
in mangrove swamps in the Antillean region.
The family Limidae includes, in addition to the common
Lima, the rare Limcea. Likewise among the Anomindae is
found the uncommon Placunanomia, as well as the ubiquitous
Anomia. The brackish-water Dreissena is not frequently
encountered among American Tertiary faunas. Of greater
interest is the presence of the extremely rare Julia, a genus
that at the present time is confined to the Indo-Pacific region
and is represented by only a few fossil species — one from the
Oligocene of Florida and two from the Miocene of south-
western France.
A minor element in the fauna is furnished by the Anomalo-
desmacea. The five species are confined to the superfamily
Poromyacea and include small forms under the families Ver-
ticordiidae, Poromyacidae and Cuspidariidae. One of the
Cuspidarias is the type of the subgenus Bowdenia Ball.
.The relative importance of the Teleodesmacea is dimin-
ished by the unusually large number of prionodonts, although
naturally the teleodonts include the bulk of the fauna.
Among the Astartacea members of the family Astartidae are
conspicuously absent, but the Crassatellitidae are represented
by five species of Crassatellites, of which the most important
and the most abundant belong to the subgenus Crassinella.
ISTo Carditas are present, but the genus Venericardia includes
a prolific Venericardia s. s. and also a small curious form
that has been referred to the subgenus Pteromeris, although
it is hardly typical of that group.
The superfamily Lucinacea is the most diversified of the
larger groups. Although only five genera are included, they
are represented by 32 species. The genus Phacoides alone
50 Pelecypods of the Bowden Fauna [248
furnishes half of the species distributed among eight sections.
Two phacoidean elements, Lucinisca and Miltha, as well as
the genus Lucina, are absent. The Codakias and Myrtaeas
are abundant and well-developed. The Divaricellas are indi-
vidually numerous, whereas the Diplodontas are, as usual,
represented by a small number of individuals.
In contrast to the richness of the lucinoids is the meager
representation of the Leptonacea. The entire superfamily
includes but four species segregated into three genera and as
many families. Furthermore, the four species are represented
by only six valves, two of which belong to the rarely encoun-
tered subgenus Basterotia of the genus Anisodonta.
Among the larger groups is the genus Cardium, represented
by seven sections and eleven species. The sections are such
as are found in any tropical or sub-tropical mid-Tertiary
American fauna, but Cerastoderma and Papyridea are not
included. The Trigoniocardias, which are peculiar to the
mid- American region, are a conspicuous element; indeed, a
species of this section is the most abundant bivalve in the
fauna.
The eight veneroid genera are divided among the sub-
families Meretricinae, Venerinae and Geminae. Chione is
the most abundant with regard to both the number of species
and individuals. Parastarte, represented by a single valve,
has heretofore not been reported outside of the Floridian
region either recent or fossil. The genus Tivela is not in-
cluded in any of the Tertiary faunas of the North American
mainland. An interesting form comparable to Cooperella in
dentition is placed in a new section of that genus. Only two
species of Cooperella are known, a Recent species from the
west coast of North America and another from the late Mio-
cene of the Atlantic Coast.
The genus Tellina includes 15 species, distributed among
6 sections. Angulus has the largest number of species, but
the most abundant forms are found under Merisca and Moe-
rella. Among the Macomas is a typical Cymatoica. The
remaining Teleodesmacea are scattered among several groups.
249] W. P. Woodring 51
A single fragmentary valve of an indeterminable Spisula is
the sole representative of the Mactridae. Two of the three
species of Corbula, the only non-boring Myacea, are exceed-
ingly abundant. The unusually favorable conditions of pre-
servation are indicated by the presence of several fragile
boring Adesmacea.
3. PHYSICAL CONDITIONS
The student of recent marine faunas would consider with
undisguised suspicion an attempt to reconstruct environ-
mental conditions on the basis of the testimony furnished by
a single element in a fauna. Despite the lack of an intensive
census of a restricted shallow-water West Indian area, which
would be of inestimable value in projecting backward the fac-
tors that determined the assemblage of an Antillean Tertiary
fauna, the ensemble of Bowden pelecypods is such as to per-
mit the offering of certain considerations, some of which are
more or less obvious and even trite.
Though it is a mere platitude to state that the fauna is
tropical, yet this facies is emphasized in a striking manner
by the development of certain groups and the absence of
others that are prominent in the Tertiary faunas of the south-
ern Atlantic Coast. The most prolific genera — Area, Pecten,
Phacoides, Cardium, Tellina — are characteristically tropical
or are represented only by sections or species that are con-
fined to low latitudes or there reach their maximum develop-
ment. According to the latest faunal lists only two of the 18
species that persist to the Recent at present range north of
Cape Hatteras — the ubiquitous Anomia simplex d'Orbigny
and Divaricella quadrisulcata (d'Orbigny). Eight are re-
corded from Hatteras southward to the West Indies or Brazil ;
seven are confined to the area south of Florida and one species
is restricted to the tropical portion of the West Coast. Vir-
tually the same proportions obtain for a large number of
Recent species that closely resemble Bowden forms.
The Areas reach their greatest importance in the warmer
52 Pelecypods of the Bowden Fauna [250
seas. The Bowden species are such as would be expected in
tropical waters ; indeed a number of them are encountered in
the present West Indian fauna. The genus Pecten is usually a
conspicuous element in the Tertiary and Eecent faunas of all
latitudes, but the large species that are characteristic of higher
latitudes, are absent. Spondylus is confined to tropical or
sub-tropic regions in the Eecent seas. In the middle and late
Tertiary faunas of the United States the genus is restricted to
rare occurrences in the Meridian region. Perhaps the most
obvious indication of the temperature of the waters is fur-
nished by the superfamily Astartacea, which is represented
only by several Crassatellites. Even the warm-water Caloosa-
hatchie and Waccamaw faunas include one or two Astartes,
but in the Bowden assemblage the genus is entirely absent.
An Echinochama, a genus which is preeminently Antillean,
is the most ponderous bivalve in the fauna. The entire group
of lucinoids is quite partial to tropical waters, although a few
species, especially of the genus Divaricella, range into high
latitudes. By far the greater number of the Cardiums are of
the ornate type that indicates a warm-water habitat. More-
over, the smooth or relatively simple forms are identical with,
or closely related to, Eecent species that do not occur north of
Florida. Although the distribution of the genus Tellina is
almost world-wide the group is predominantly tropical.
In attempting to determine the depth of the water from a
consideration of the bathymetric range of identical or closely
related Eecent species a rigid adherence to the evidence fur-
nished by dredging records would often lead to absurd con-
clusions. An example is furnished by the genus Limopsis, of
which two species are present. According to available data
the group as a whole is characteristic of deeper water, yet
several species occur in Eocene beds of the Gulf Coast that
undoubtedly were deposited in very shallow water.
The fauna is essentially a shallow- water fauna. All of the
Eecent species occur in water of shallow depth and many have
been recorded from the intertidal zone, but the range of sev-
251] W. P. Wo'odring 53
eral is extended into considerably deeper water. The presence
of apparently deeper water elements, such as Tindaria and
Bathyarca, may be the result of the action of currents or other
extra-limital factors. Since but a single valve of Tindaria is
present it is doubtful whether the form was indigenous. It
may be suggested that the depth did not exceed 30 or 40
fathoms and it is highly probable that the bulk of the fauna
lived in water that was considerably shallower.
The waters were clear and the bottoms free from mud. By
far the larger number of the Bowden pelecypods are partial
to bottoms of sand or fine gravel; even the burro wers are
usually found on sandy bottoms. The absence of Mulinia
and related forms that prefer a muddy bottom is not without
significance. The meager representation or absence of the
Leptonacea and other small forms that usually frequent
muddy bottoms in sheltered near-shore positions or are
attached to algae indicates an open coast and rather strong
current action. Estuaries interrupted the coast line and led
back to the streams that supplied the relatively coarse volcanic
debris which constituted the bulk of the sediments. From the
estuaries valves of Dreissena and the mangrove-oyster were
carried down to the coast and mixed with the indigenous beach
and off-shore dwellers.
4. EELATIONS TO THE FAUNAS OF THE NORTH AMERICAN
MAINLAND
The possibility of comparing an Antillean Tertiary fauna
with those of the Floridian Peninsula is enhanced by the
proximity of the areas and by the succession of tropical or
sub-tropical faunas of the mainland. Dall11 has correlated
the Bowden horizon with the top of the Alum Bluff formation
which includes the Chipola, Oak Grove and Shoal Eiver mem-
bers in ascending order. According to Dall 12 the Chipola
"Ball, W. H., Trans. Wagner Free Inst. Sci., Philadelphia, vol. 3,
pt. 6, pp. 1560, 1582, 1903; Bull. U. 8. Nat. Mus. 90, p. 8, 1916.
12 Dall, W. H., loc. tit., p. 1574, 1903.
54 Pelecypods of the Bowden Fauna [252
fauna indicates distinctly sub-tropical conditions. Berry 13
has shown that the Alum Bluff flora is sub-tropical or very
warm temperate and according to Dall 14 the Oak Grove fauna
indicates a slight lowering of temperature. Above the Alum
Bluff formation is a sharp break that has been seized upon as
a convenient location for the division between the Oliocene
and Miocene. Though the succeeding Miocene faunas of
Florida are imperfectly known they unquestionably indicate
a more temperate f acies 15 and occupy a position near the
middle of the Miocene series of Virginia and the Carolinas.
The Pliocene Caloosahatchie formation of Florida has yielded
a rich sub-tropical fauna.
The profound hiatus in the Floridian succession is par-
tially bridged by the Miocene deposits of Virginia and the
Carolinas. According to Berry 16 the Calvert formation,
which is the oldest, is middle Miocene, probably Tortonian.
The only faunas of this region that present a warm-water
f acies are those of the late Miocene Duplin and the succeeding
Pliocene Waccamaw, both of which are warm temperate rather
than sub-tropical. It is apparent that an attempt to compare
a mid-Tertiary Antillean fauna with the faunas of Florida is
seriously hampered by the absence of any tropical or sub-
tropical Miocene faunas on the mainland. Furthermore, in
order to make comparisons with any warm-water Miocene
fauna of the Atlantic Coast it is necessary to resort to the
geographically distant warm temperate Duplin fauna. In
Florida the only post- Alum Bluff marine assemblage that
flourished under conditions in any manner comparable to
those of an Antillean fauna is the sub-tropical Pliocene
Caloosahatchie fauna, which is appreciably younger than the
slightly more temperate Waccamaw fauna.
"Berry, E. W., U. S. Geol. Survey Prof., Paper 98-E, pp. 43-44,
1916.
"Ball, W. H., loo. tit., pp. 1549, 1581, 1588-1589, 1903.
15 Dall, W. H., loc. tit., pp. 1549, 1589, 1594, 1903.
"Berry, E. W., U. S. Geol. Survey Prof., Paper 98-F, p. 66, 1916.
253] W. P. Woodring 55
The Chipola marl among the Florida horizons has the
largest number of species in common with the Bowden. The
actual number is of little significance since the Caloosahatchie
has almost the same number. It is significant, however, that
the Chipolan elements are completely overshadowed by the
closer affinities of a large number of groups with Duplin and
even "Waccamaw and Caloosahatchie forms. Difficulties are
encountered in interpreting these modern elements in terms
of age relations to the faunas of the mainland, since obviously
considerations of facies and geographical proximity are
involved. A larger number of Bowden species are found in
the present West Indian waters than in any of the Florida
Tertiary faunas and more forms are common to the Caloosa-
hatchie than to the Oak Grove, Duplin or Waccamaw.
The taxodonts supply one-third of the total number of
Recent species and all of these are found among the Arcidae,
hence that family, and especially the sub-family Arcinae, has
a modern aspect. Five Eecent Areas are included in the list
and several others are very closely allied to Eecent forms.
Four of the Areas that persist to the Recent are found in the
Chipola fauna and three in the older Tampa, so that the
actual number is of little weight. But a modern element is
furnished by the introduction of the section Bathyarca. Two
of the three oysters are believed to be identical with Recent
species. Among the Pectens are several elements that are not
encountered among the Oliocene faunas of Florida; these
include an Euvola of modern aspect, several Acquipectens that
are most closely related to Pliocene or Recent forms and a
Propeamusium of decidedly modern type. Among the remain-
ing Prionodesmacea the genera Limcea and Placuanomm are
unrepresented in the Oligocene of the Florida section. •
A Crassinella strongly suggests a Duplin and Waccamaw
species. Aside from a Recent Chama, the presence of the
genus EcJiinocJiama lends to the Chamidae a modern appear-
ance. The Lucinacea as a whole present a modern aspect.
In addition to several species that are more closely related to
56 Pelecypods of the Bowden Fauna [254
Duplin or later forms,, this relation is emphasized by the
initial appearance of the section Pleurolucina of the genus
Phacoides. Although the section Eulopia of Myrtaea has
been reported from the Tampa fauna, it reaches its earliest
development of any importance in the Bowden fauna and is
not present in any of the post-Tampa Florida deposits. A
peculiar Hare represents a type that has not been recognized
except in the Eecent seas and typical Bellucinas have not been
reported from horizons lower than the Duplin. The super-
family under discussion includes a Eecent Divaricella and also
a Recent Diplodonta, which is unknown from any intervening
horizon. Two Eecent Cardiums, a Fragum and a Laevi-
cardium, are confined to Miocene and later horizons on the
mainland,, and Trachycardium includes a type unknown from
beds earlier than Pliocene. The Yeneridae supply a quota of
later Tertiary elements. The Bowden Tivela is the only rep-
resentative of the genus recorded from American Tertiary
deposits and a Recent species of Gafrarium (Gouldia)}ias not
been recognized at any other Tertiary horizon. The single
Cyclinella is very close to a Recent species and the most abund-
ant Chione s. s. is allied to a Duplin form. The genus Paras-
tarte, unrecorded from a pre-Miocene horizon, is represented
by a species scarcely distinguishable from the Miocene to
Recent type of the genus. Among the Tellinacea are to be
noted a Recent Strigilla, a Semele that is surprisingly close to
a Pliocene and Recent form and the initial appearance of the
subgenus Cymatoica of the genus Macoma.
Though many of the post-Chipolan elements are found
among the characteristically tropical groups, yet the introduc-
tion of super-specific groups, some of which are not exclu-
sively tropical, can hardly be disregarded. The Bowden pele-
cypods are distinctly younger than those of the Alum Bluff
faunas, as those faunas are now known. It may be suggested
that the Bowden fauna is Burdigalian, that is, Lower Miocene
in the sense of most American stratigraphers.
255] F. Reeves 57
ORIGIN OF THE NATURAL BRINES OF OIL FIELDS
By FRANK BEEVES
The origin of the concentrated brines so universally found
in oil-bearing strata and other porous, unmetamorphosed
rocks lying at depths below the zone of active circulating
ground water has never been definitely established. By some
these waters are thought to be of meteoric or surface origin,
t. e., they are rain waters which have in passing downward
through the strata dissolved out of the rock material the salts
which they now hold in solution. Others consider them to be
the sea water which has remained in the pores of the strata
ever since their deposition.
A study of the occurrence and chemical nature of the brines
found in the oil sands of southwestern Pennsylvania and West
Virginia furnishes data which indicate that the waters in this
area are connate or of ocean origin. This conclusion is based
on the following lines of evidence :
(1) The distribution of the water suggests that it is not of
meteoric origin.
(2) There are no adequate explanations of how the water
of deposition has been removed from the strata. •
(3) The association of the dry sands and "red beds5' of
the area indicate that the water present accumulated with the
sediments as they were being deposited.
(4) The chemical nature of the brine points to it being of
connate origin.
THE DISTRIBUTION" OF WATER
In order to consider this phase of the evidence it will be
necessary to describe briefly the structural and stratigraphic
features of the area under discussion.
Structure of the Area. — The brines occur in the Car-
boniferous and Devonian strata of the Appalachian coal basin.
58 Natural Brines of Oil Fields [256
This is a shallow geosyncline in which the surface rocks are
chiefly of Pennsylvania!! age except where in the center of the
basin there are from 800 to 1300 feet of Permian strata over-
lying the Pennsylvanian. In this area the Mississippian and
Devonian rocks underly the surface at from 1600 to 2000
feet and 2200 to 3000 feet, respectively. Around the rim of
the basin these strata outcrop. On the east they reach the
surface along the Alleghany front and on the west in central
Ohio. The distance across the center of the basin from
outcrop to outcrop of the Devonian strata is about 180
miles. The difference in elevation between the highest and
lowest point which the same strata attain is about 8000 feet.
Thus it is apparent that the geosyncline is to be considered
as a very shallow basin. Across the basin and paralleling the
Appalachian mountain folds, the strata are folded into a
series of minor anticlines and synclines. Towards the east-
ern outcrop these flexures become more and more pronounced.
In this area the dip along the flank of the folds is about
200 feet to the mile, while in the central part of the basin it
seldom exceeds 75 feet to the mile. Westward the folds die
out almost entirely and the strata rise to the surface in central
Ohio at the rate of about 30 feet to the mile. The strata
under consideration therefore are comparatively little folded
and consequently little metamorphosed. Faulting is also
absent except for a minor fault of a few miles in extent in
central West Virginia. Southward across Kentucky and
Tennessee the basin narrows and the strata are folded and
faulted to a greater degree. On this account and also because
of the lack of data on the deep underground waters of the
area that part of the basin is not included in this discussion.
The northern end of the basin is also not considered here be-
cause in that area meteoric water has entered, through old
abandoned oil wells, the deeper sands and destroyed more or
less the original water content of these strata.
Stratigraphy of the Area. — The drill has penetrated strata
from the Permian to the Lower Devonian in the search of
oil in the central part of the basin. The Permian and Penn-
257] F. Reeves 59
sylvanian are the surface rocks. They comprise a series of
from 2000 to 2500 feet of alternating thin-bedded shales,
sandstones, limestones, clays, and coals. The Mississippian
underlies the Pennsylvanian unconformably. It is made up
of about 800 feet of sandstone, shales, and limestones which
vary in thickness from 100 to 250 feet. The Catskill forma-
tion is a non-marine facies of the Upper Devonian. It con-
sists of from 500 to 800 feet of thin-bedded sandstones and
red and dark-colored shales. Below the Catskill occur about
300,0 feet of compact shales. Underlying these are the Lower
Devonian limestones.
Occurrence of the Water. — Water is found in the sandstone
and limestone members of the above stratigraphic series. In
these it occurs in porous layers in which also occur oil and
gas. Usually there is a structural arrangement of these
materials. Generally the water occupies the synclines, the
gas the anticlines, and the oil intermediate structural posi-
tions. This distribution is modified by the amount of water
in the sands. Where they are saturated the oil occupies the
anticlinal areas. In the Appalachian oil fields, however, the
most common condition encountered is where there is but
sufficient water to fill up the synclines. The oil, under such
conditions, occupies a belt structurally higher and the gas fills
up the anticlinal areas. In sands that contain no water the
oil is found in the synclines.
The amount of water in a sand is usually thought to be a
function of its depth. In general it may be stated that the
Pennsylvanian sands are saturated, the Mississippian sands
semisaturated, and the Catskill sands dry. This would appear
to support the idea that the water present is meteoric in ori-
gin. On examining the facts, however, this assumption does
not appear to be justified for the water does not disappear
with depth. Two deep wells which have penetrated the Lower
Devonian strata have revealed the fact that below the dry
Catskill sands are prolific water-bearing strata at depths from
5000 to 6000 feet. This occurrence, as well as the universal
appearance of water at all depths in other oil fields, indicates
60 Natural Brines of Oil Fields [258
that depth is not a factor in the disappearance of water. This
being so, then the usual argument that the water present has
originated from descending waters loses weight. The presence
of nonwater bearing sands such as the Catskill occurring
between saturated strata goes to show that there has been no
downward movement of meteoric water across the strata. Thus,
on the assumption that the water present has a surface origin
it must, then, have reached its present position by entering
the strata at their outcrop. This undoubtedly explains the
source of the waters occurring in strata of Pennsylvanian age,
for these are saturated up to their outcrops with water obvi-
ously of surface origin. But the saline waters in the Missis-
sippi sandstones are not present towards their eastern outcrop.
The synclines along the eastern flank of the basin contain
no water and these would have to be filled before water could
reach areas in the sands west of them. It is impossible that
the water could have come from the westward for some of
the sands, i. e., the Maxton and Hundred-foot sands, are not
continuous to the western outcrop of the formations. Thus
with these facts opposing the possibility of a vertical or lateral
movement of the water it must be considered to be of connate
origin.
METHOD OF KEMOVAL OF WATER OF DEPOSITION
The processes usually suggested by which the sediments
have been depleted of the water deposited with them are
hydration, consolidation of the sediments, expansion and
evaporation of the water due to heat, and drainage resulting
from elevation.
A brief consideration of these hypotheses is .sufficient to
prove their ineffectiveness.
Hydration cannot have been a factor in the removal of the
water for the few minerals of sedimentary strata capable of
combining with water would more likely be hydrated while
they were accumulating as water-borne sediments than while
ihey were subjected to the heat and pressure incident to their
condition of deeply buried strata.
259] F. Reeves 61
Consolidation of sediments though effective in lowering
the amount of pore space does not remove the water from the
porous area that remains after consolidation, so such an
action tends to increase rather than decrease the per cent, of
saturation of the total porosity of the rocks.
The influence of heat resulting from the expansion and
contraction following periods of burial and exposure due to
erosion can be no effective agent in removing the water since
water increases only 4 per cent in volume when it is raised
from a temperature of 4 degrees Centigrade to 100 degrees
Centigrade and this represents a much greater change in
temperature of rock strata than ever occurs in a geologic
cycle.
Drainage in an area of the nature of the Alleghany coal
basin is not possible since the basin is~ so shaped that the
water cannot drain out of it. Moreover,, these sands are
below sea level and hence not subject to drainage.
Thus with no adequate explanation of how sea water has
been removed from rock strata it is more logical to consider
the water present to be of connate rather than of meteoric
origin.
THE ASSOCIATION OF THE DRY SANDS AND " EED BEDS "
A study of the non-water-bearing strata of the Appalachian
oil fields has furnished data which is to be interpreted as
furnishing positive evidence that the waters present in these
sands are connate in origin. As mentioned above the Cats-
kill and certain areas of the Mississippian sands contain no
water. This absence of water is not due to structural or
porosity conditions but it is characteristic of sands which are
associated with red shales. Several lines of evidence indicate
that these dry areas and the " red beds " were developed when
the sediments were exposed as flood-plain deposits to the ac-
tion of air which oxidized the ferrous minerals present and
at the same time dried out the sediments, in which condition
they have remained to the present time. The acceptance of
this conclusion, the arguments in support of which are given
62 Natural Brines of Oil Fields [260
elsewhere/ results in attributing a connate origin to the
water present.
THE CHEMICAL NATURE OF THE WATER
The following is a mean analysis of 8 brines collected
from strata of Mississippian age expressed in parts per
million parts of water :
Si02 137 Na 41585
Fe 26 K 307
Ca 12740 Br 44
Mg 2295
Hc03 19 Total 153000 parts of
S04 1530 dissolved matter per million
Cl 95043 parts of water
The outstanding feature of the water is its high chlorine
content. This makes up about the entire acidity of the water
and comprises 61.12 per cent, of the total dissolved matter
present. The other negative ions present, HC03 and S04,
occur in small amounts, making up but about one per cent,
of the salts present. Sodium is by far the most abundant of
the basic ions and comprises 21.18 per cent, of the material
in solution. Calcium is about one-third as abundant as so-
dium and consists of 8.33 per cent of the total salts present.
The other basic ions occur in unimportant amounts.
In addition to their peculiar chemical nature the brines
are also to be distinguished by their concentration, which is
from three to seven times as great as ocean water. Another
interesting feature is the similarity in content of the consti-
tuents carried by the waters. Reference to the analysis on
page will show that the various salts are always present
in about the same relative amounts. This is the more strik-
ing when it is considered that the waters were collected at
points over an area of 10,000 square miles and from horizons
of different geologic age occurring at depths of from 1000 to
beeves, Frank: A Discussion of the Absence of Water in Certain
Petroleum-bearing Strata of the Appalachian Oil Fields. Disserta-
tion in Johns Hopkins University Library.
261]
F. Reeves
63
p
E
/ *
/ ,/
1
/
\ /
f
O
(i
d
*
a
i
i
DLJ
4 i
f I,
f i
j i
? i
•
\
Graphs showing the amount of each ion (expressed in per cent, of
the total salts present) in the brines collected from Pennsylvania,
Mississippi, Catskill and Lower Devonian strata and in the average
Ocean (O) and river waters (R) of the world.
64 Natural Brines of Oil Fields [262
6000 feet. A slight change in chemical nature with depth
is noticed which may be a function of stratigraphic horizon.
This possibility will be discussed later.
Obviously the brines are not like ocean waters yet they
are more unlike surface waters and since they are to be con-
sidered as originating from one of these sources it is logical
to attribute them to that one which they more nearly resem-
ble as this requires the explanation of fewer anomalies in
the transition from the one water to the other.
This comparison is shown graphically on page 63. On
the horizontal lines P, M, C, D, are plotted, in percentage of
total salts present, the amount of each ion in the four mean
analyses of the brines from the sands of the Pennsylvanian,
Mississippian, Catskill, and Lower Devonian, respectively.
On line S is plotted also the percentages of the salts in
the mean analyses of ocean and surface waters. With a line
drawn through these points a clear idea is obtained of the
similarity between the brines and their two possible sources.
On the assumption that the brines are surface waters which
owe their present chemical nature to changes which they have
undergone as they passed downward through the rock ma-
terial, it would be expected that with increase of depth there
would be a progressive change at least to a point of satura-
tion. Thus, for example, since there is a decrease say of
calcium in the first 1300 feet of from 20.39 per cent, to 8-33
per cent., at greater depth it would be expected that the
deeper brines would continue to show a decrease in the
amount of this ion present. Reference to the graph shows
that instead there is a decided increase of calcium with in-
crease in depth below 1300 feet. Sodium shows the same
anomalous change with depth. It is apparent, on the other
hand, that, with the exception of magnesium, the ocean
waters fall more in the general alignment of the graphs than
do the surface waters. Of course it may be argued that the
water would undergo a greater chemical change in the surface
strata or in the zone of oxidation than at subsequent depths,
263]
F. Reeves
ater
water
Lower g Catskill
Dev. 0 £
Mississippi
65
Pennsylvanian
oscn O o i— ' co >£>. co SB o H*1 ^ to to to _OH- 'H-H- 'H-itotototo & o
> , ^_* (& Ht» -~— •- ^-— ' -^^ ^_* Ht) -• — - — >. • ^^ *. ^ Cj? Ht» ^_^ ^_^ ^_^ ^_^ ^^ ^_^ ^^ N ., £3 *-fc
3 a,
<D IS
•^ S S °° ^ ° ^ to o
^ ooo-ao t^toos
H-i IO tO H- H-1 tO !-• ^ [0 h-i tO tO I-i I-i H- "Tt H-1 I-- H- H- H" ^
i— i o os to -<r -<rOooOO-<ico^ co oscococotot'S
i ^g^i§i§;g s §§§§§§
os eo o o to to eo
b
. . . . o o i-1 H-I •
. • . • os H- en cn •
bs en f_i o
OS O
b b
to to i— i
pppo^oo oo cocopenoo^ipoQo t^
eo -j co eo -<i oo
I <$?
£? t— '
q STS"^ ^"Q cn
r-^ If £J2
bl ^» -N
CO
tO tO h-J i— i H-i H-I J-
coben to co^bs^eo c
rf^-ito COH^C^OC
csoeo
enb
i-'to
enco
to co i-1 o°
CO °° <=>
Co S^ '
s _ -
o
o .
— I tO O
CO ^C CO
O O O h-
rfi> tO tO CO
22S §
-d to -^
co o H-I o o
co to HI co co
H-I H-I O C O O "h-lCOH-ICO
OS CO OS 00 CO O CO
Zi S' so
OJ ,
? i 3
t> en
w. en en
80 bs to
ig o°co
*Q ST1
SQ" tij
to H-
tO H-I
OS OSOSOSOS OS OSO5OSOSOS OS OSOSOSOSOSOSOSOS OS Q5
H-I p H-I tO tO H-l H-I H-I tO H-J H-l tO pi H-i H-> p tO tO tO I-* P O
to co co bs co co *>• to i—i co H-I H-I co co to '\—> to b co co
OH-I tOH-ios^-to ^lootoco eo
tO tO tO tO H-I tO tO tO tO
H-I' H-IJH-COOO p en-<i-<i
^4 bi * co bo H-I to
H-I Ol OS OS GO
to to
to to to co
to ^j os p
H-i CO CO I—"
to o
rfx co os en t^.
H-i *^I CO OS
to eo to co eo co
' ' ' co bs ^
OS O OO ^ H-i tO ^
H- W
CO
co to • cn en
os • co to
en cn
0 00
. bo cnoos^
ba
to tOtOn-ico H-I H-tOi— IH-IH-I H-I
os r4 flft CD O *>• ^l p to p H-I en
bs co to co bs bo co co H-" bo cc
" h- O
H- CO O
66 Natural Brines of Oil Fields [264
but it is hardly possible that the reactions between the
waters and the rock material would produce a brine so simi-
lar to ocean water, since the alteration of river water to ocean
water is effected largely by the action of organisms in the
sea.
The perpendicularity of the lines uniting the brines and
the ocean water indicate the similarity between the chemical
nature of the present ocean and that of former seas. The
variations from the straight line,, with the exception of the
graphs for calcium and sodium, is readily explained by the
possible reactions which may have occurred between the rock
material and the chemicals in solution. It will be noted,
however, that there is a definite increase of calcium and
decrease in sodium in passing downward from the Pennsyl-
vanian to the Lower Devonian brines. If the waters are
assumed to be of meteoric origin, then there is the anomaly
of the more soluble sodium being replaced by the less soluble
calcium ion as the water penetrates the earth's crust. If,
however, the waters are considered to be of connate origin,
then this change in depth may be a function of the geological
age of the strata and hence indicate changes in the chemical
content of the ocean during different geologic periods.
If the salts of the ocean have been added by the rivers,
then, of course, the salinity of the ocean would increa.se with
the age of the earth. This increase in salinity will not affect
the chemical nature of the water if the relative amount of each
salt remains constant. However, since organic matter and
changes in physical conditions remove some salts from solu-
tion, the waters will change in nature as well as concentration.
Thus the relative increase in sodium may be explained by
the fact that but little of the enormous amount of this salt
added continually by the rivers is lost by the ocean, while
most of the other salts are constantly being removed from
solution. The variation in amount of calcium in the differ-
ent brines is likely due to fluctuation in the amount of C02
in the air during different geologic periods. This fluctuation
265] F. Reeves 67
is a generally accepted fact 2 and since there is an equilibrium
between the amount of the C02 in the air and in the sea
water it is to be expected that the sea water at times, when
there is the greatest amount of C02 in the atmosphere, will
hold a comparatively larger amount of calcium in solution
as the solubility of calcium carbonate is a direct function of
the amount of C02 present.3
The increase in concentration with depth is also an argu-
ment that the brines are indigenous to the rocks in which
they occur. Kichardson,4 however, suggests that this is due to
the fact that there has been an upward diffusion of salts from
the rock salt deposits that are known to underly the strata
in question. But it has been pointed out that there are dry
sands in the area under consideration intervening between
these lower water-bearing horizons and the Mississippian
sands and, as diffusion through dry strata is impossible, this
suggestion seems untenable. Again, on this assumption it is
difficult to understand why sodium would increase in relative
amount with increase in distance from the salt beds. Refer-
ence to the analysis given will show that the Pennsylvanian
brines are richer in this salt than the Lower Devonian. It
appears more likely that the concentration is due to a capil-
lary migration of the water away from the sands in which it
occurs and in which it accumulated. This migration would
remove part of the water and most likely leave the salt behind,
because fine-grained sediments have an absorptive effect on
solutions passing through them 5 which would result in a
2 Chamberlain, T. C. " The influence of great epochs of limestone
formation on the constitution of the atmosphere." Jour. Geol., vol.
vi, 1898, pp. 609-621.
3 Johnson, John and Williamson, E. D. "The rOle of inorganic
agencies in the deposition of calcium carbonate." Jour. Geol., vol.
xxix, No. 8, 1916, pp. 729-750.
4 Richardson, G. B. " Note on the diffusion of sodium chloride in
Appalachian oil field waters." Jour. Wash. Acad. Sci., vol. vii, no. 3,
1917, pp. 73-75.
6 Turrentine, J. W. " The occurrence of potassium salts in the
saline of the United States." Bureau of Soils, Bull. 94, 1913.
68 Upper Cretdceous Seacoast in Montana [266
greater concentration of the waters. Considering this fact,
then, the waters should show a decrease rather than an in-
crease of mineral matter with depth, if the waters were of
surface origin. Which adds more evidence to the above, that
these natural brines are of connate origin.
AN UPPER CRETACEOUS SEACOAST IN MONTANA1
By W. T. THOM, JR.
INTRODUCTION
The nonpersistence of lithologic units is the greatest ob-
stacle to systematic stratigraphic work and correlation. Par-
ticularly is this true when it is necessary to determine the
relationship of marine and continental deposits. That this
difficulty may be largely overcome by a correct " paleophysio-
graphic " perspective of the period dealt with is now becoming
the accepted doctrine ; and the writer has undertaken this
sketch both as an illustration of the way in which ancient
physiographic conditions may be deciphered and as a demon-
stration of the close genetic relationship of some of the differ-
ent lithologic phases of the Judith River formation.
The writer studied this formation in the area lying north
of the Yellowstone Biver, near Billings, Mont., while serving
as an assistant to Eugene T. Hancock, of the United States
Geological Survey, and it is with his very kind consent that
this article is published. The accompanying sketch map will
serve as a geographic guide to the reader in following the
discussion.
STRATIGRAPHIC GEOLOGY
The later Upper Cretaceous sediments of the Montana
group are exposed throughout this region, forming about 90
1 Published by permission of the Director of the United States
Geological Survey.
167]
W. T. Thorn
69
per cent, of the rocks outcropping within its limits. Five
formational subdivisions of the Montana are present, which
are, in ascending order, the Eagle sandstone, Claggett shale,
Judith Eiver formation, Bearpaw shale, and Lennep sand-
stone. The relationship of these units is perhaps best brought
out by the accompanying diagram, but a brief description of
each formtion may make the details clearer.
The Eagle sandstone is developed in this area as the marine
sandstone apex of a wedge of continental sediments built sea-
ward at the close of Colorado time. The strand origin of the
FIG. 1. Sketch map of an area in Montana.
upper part of the formation seems clearly indicated by abun-
dant impressions of the fossil seaweed Halymenites major, by
the coarse grain of the sandstone, and by the almost universal
distribution of small, flattened chert pebbles at or near the
top of the formation. The Judith Eiver formation is much
like the Eagle in mode of origin, but is thicker and shows the
development of fresh-water and estuarine phases much farther
east than the Eagle. The Lennep sandstone constitutes a
third continental wedge, chiefly notable for the predominance
of volcanic material among its component sediments. Separ-
ating these strand and coastal-plain deposits are the marine
shales of the Claggett and Bearpaw formations, which thin
westward and disappear at an indeterminate distance beyond
the border of the area under consideration.
70 Upper Cretaceous Seacoast in Montana [268
From this and from other evidence at hand it seems rea-
sonably certain that the strand lines of the late Mesozoic lay
nearly parallel to the present Eocky Mountain front, and
that it migrated to and fro in response to the recurrent
depressive movements of the period, which were gradually
counterbalanced by intervening intervals of sedimentation.
DISTRIBUTION AND CHARACTER OF THE JUDITH RIVER SEDI-
MENTS
The sediments of the Judith River formation are now well
exposed north of Billings by reason of the extensive denuda-
tion which the region has undergone; hence it is possible to
form an accurate estimate of the variations of the section,
both vertically and horizontally.
Near Gibson, 50 miles northwest of Billings, the formation
is of freshwater origin and consists of sandy .shale and nu-
merous beds of hard, rather muddy, quartizitic sandstone
containing reed stems and fragments of coniferous material.
Both shale and sandstone are characteristically of a yellowish
or tawny hue, though some of the beds, particularly among
the softer units, indicate by their texture and peculiar green-
ish brown color the presence of the tuffaceous material which
was thrown out so copiously by the volcanoes of the Crazy
Mountains during later Upper Cretaceous and early Eocene
time.
Farther east the volcanic material disappears and the sec-
tion gradually assumes the aspect typical of the formation as
it is developed along the Missouri and in the vicinity of
Havre on Milk River; an alternation of light-gray to white
clay shales with lignitic shale and carbonaceous sandstone
giving the exposures a peculiar striped appearance. With
the advent of the carbonaceous zones in the section the
brackish water shell Ostrea subtrigonalis also makes its ap-
pearance at different horizons in the area immediately north
of Broadview, though it is conspicuously present in but a
single very thick shell bed of extraordinary uniformity and
269] W. T. Thorn 71
persistence of development which lies about 50 feet above the
basal sandstone of the formation.
At Acton, 15 miles northwest of Billings, the formation
still retains its characteristic appearance and lithology, but
east of the town a very rapid lateral variation of the sedi-
ments soon Incomes apparent. The thin carbonaceous sand-
stones of the western section rapidly increase in magnitude
and in coarseness of grain to the eastward, individual mem-
bers increasing from 6 or 8 to as much as 50 feet in thickness
within a distance of 5 miles. As a result the formation, as
exposed about 6 miles east of Acton, consists of four massive
sandstones separated by intervals of shaly sandstone or sandy
shale. Abundant impressions of Halymenites major occur
throughout these sandstones and indicate the inception of
strand conditions, a conclusion confirmed by the discovery
of marine fossils a few miles farther east, near Huntley.
From where the maximum of sandstone development is
attained, 6 miles east of Acton, the lower sandstone members
begin to taper eastward, merging into shale lithologically
indistinguishable from that of the underlying Claggett.
It is further to be noted that certain surprising features
of the Judith River-Bearpaw contact appear southeast of
Gibson. Long, narrow ridges capped by hard andesitic sand-
stone are developed for considerable distances, especially near
Big Lake in the so-called Lake Basin region, their general
extension being from east to west or from southeast to north-
west. The cap sandstones of these ridges were probably
never continuous over the intervening areas, but they lie at
practically an identical horizon and are so similar lithologi-
cally that they are certainly the products of the same agency.
Below these upper dark sandstones the section shows
great variability; at some localities sandy beds containing
more or less carbonaceous shale and lignite occupy the whole
of the interval down to the more typical Judith River sedi-
ments, while elsewhere, even in the same ridge, the cap
sandstone may overlie typical Bearpaw shale with only a
72
Upper Cretaceous Seacoast in Montana [270
few feet of thin-bedded white sandstone intervening. From
this and from other corroborative evidence the conclusion
therefore seems natural that the ridges represent the radiat-
ing channel sandstones of an ancient delta, which was built
out into the marine waters of the incipient Bearpaw sea by
a river of considerable size flowing from the south or south-
west.
MONTANA
Colorado
FIG. 2. Section showing the relation of the sediments.
PALEO GEOGRAPHIC INTERPRETATION
Upon the basis of the foregoing data the writer draws the
following picture of the physiography of Judith River time.
The low coastal plain of the mainland lay to the east of the
Crazy Mountains, very possibly extending thence a little
beyond Gibson, and upon it a gradually increasing thickness
of freshwater and subaerial deposits was laid down as regional
subsidence progressed. Simultaneously a sandy barrier beach
was developed and maintained in the area east of Acton, thus
partially shutting off a shallow embayment or lagoon whose
quiet waters, rendered brackish by the regional drainage,
271] W. T. Thorn 73
afforded a favorable habitat for multitudes of oysters,, which
were later buried by the burden of fine silt accumulating in
the quiet waters of the bay. Still later, as sedimentation
gained upon subsidence, the site of the one-time oyste'r bed
became the location of repeated coastal swamps, in which
were formed the lignitic beds and carbonaceous zones now so
conspicuous in the upper part of the formation.
Subsequent revival of the local depressive movements of
the crust temporarily restored the old embayment, into the
southern end of which a large river built out a delta, even as
the marine shales of the Bearpaw were being laid down in
the deeper part of the bay a little farther north. As a final
phase more rapid depression carried marine waters farther
westward, and the Bearpaw sea covered the whole area.
A REMARKABLE UPPER CRETACEOUS FAUNA FROM
TENNESSEE *
By BRUCE WADE
During the summer of 1915 the Tennessee Geological
Survey located well-preserved fossils in the Eipley formation
in the northeastern part of MclSTairy County, Tennsesee. An
incomplete collection was made from the locality in this
region where the strata containing the fossils are best ex-
posed. This collection was studied during the winter in the
Geological Laboratory of the Johns Hopkins University.
This partial study of the fauna has resulted in the differen-
tiation of nearly 300 species, and investigations show that no
single locality yet reported from the Cretaceous of North
America has furnished such a large fauna made up of such
well-preserved shells.
The Gastropods are unusually abundant and include not only
1 Published with the permission of Dr. A. H. Purdue, State Geolo-
gist of Tennessee.
74 Upper Cretaceous Fauna from Tennessee [272
a large number of new species but several forms which are
regarded as new genera.2 Further collections were made at
this place and in the adjoining regions during the field-
season of 1916. The writer has begun, for the Tennessee
Geological Survey, an investigation of all the Upper Cre-
taceous deposits of the state and hopes to submit in the near
future a detailed report on the Stratigraphy and Systematic
Paleontology of these rocks.
GENERAL GEOLOGICAL EELATIONS.
The Upper Cretaceous deposits of Tennessee outcrop in a
wedge-shaped area which crosses the State in a nearly
north and south direction, and lies largely west of the Ten-
nessee Eiver in the west-central part of the State. This area
is about 67 miles wide along the southern boundary of the
State, narrowing to the northward until at the Kentucky
line it is only about 15 miles in width.3 Along the southern
border of the State in Wayne, Hardin, McNairy and Harde-
man counties these deposits may be segregated into the fol-
lowing lithologic units.
f Owl Creek horizon
-r>. , „ ! McNairy sand member
Eipley formation J _ . .
] Ferruginous clay horizon
[Coon Creek horizon
Selma chalk
Eutaw formation
Tuscaloosa formation
The present discussion is limited to the lower part of the
Eipley. This formation covers the western two-thirds of
McNairy County, and in general is well exposed over that
entire region. The four horizons or members of the Eipley
2 Some of these have been described in the Proc. Phila. Acad. Nat.
8ci., 1916, pp. 455-471, pi. 23, 24.
3 Jenkins, 0. P., Geological Map of Tennessee, State Geol. Survey,
1915.
273] B. Wade 75
named above may be traced across the county by their con-
tained faunas and lithology, even though there are no sharp
lines of demarcation separating the one from the other. The
sediments of the Coon Creek horizon, which are described in
detail below, are quite variable, ranging from local lenses of
impure limestone through very fossiliferous marls to glau-
conitic sands and gypsiferous clays poor in fossils. The
overlying ferruginous clay horizon is sparsely fossiliferous
and extends across the county in a belt about three miles
wide. The McNairy sand member next above, which is
typically exposed in McNairy county, has been described by
Stephenson.4 This member is essentially a sand and has
yielded few fossils. The so-called fucoid Halymenites major
Lesq. occurs sparingly. In 1915 leaves were collected from
near Selmer, Tenn., and Big Cut, Tenn., the type section for
this number. These have been submitted to Prof. E. W.
Berry for study. Above the McNairy sand and exposed
along southwestern McNairy County and southeastern Har-
din County is a fossiliferous horizon which may be traced
southward into Mississippi to Owl Creek, the type locality for
the Ripley formation.
COON CREEK LOCALITY AND ITS STRATIGRAPHIC POSITION.
The locality under immediate discussion may be known as
the Dave Weeks place on Coon Creek. It is in the north-
eastern part of McNairy County, 3% miles south of Enville
and 7% miles north of Adams ville and % mile east of the
main Henderson-Adamsville Road. The beds containing the
fossils are best exposed in the valley about two hundred and
fifty yards east of Dave Weeks' house along the headwaters of
Coon Creek. This is a small .stream flowing northward into
White Oak Creek, a tributary of the Tennessee River.
Upper Cretaceous fossils have been previously collected
4 Stephenson, L. W., U. S. Geological Survey, 1914, Prof. Paper
81, p. 22.
76 Upper Cretaceous Fauna from Tennessee [274
from a few places in this general region of the Mississippi
radius of 7% miles of the Dave Weeks' place. At a point %
mile west of Adamsville Stephenson 5 made a collection from
the Exogyra ponderosa zone of the Selma chalk. Four miles
northeast of Adamsville he made another collection from the
same zone at a locality referred to as " four miles southwest
of Coffee Landing." Three miles west of Adamsville fossils
were found by Stephenson in the Exogyra costata zone of the
Selma chalk. About eleven miles southwest of the Coon
Creek locality and "two and one-half miles east of Purdy,"
Safford6 collected in the uppermost part of the formation
which he designated as the " Green Sand." The horizon
from which this last collection was made probably has the
same stratigraphic position as the Coon Creek beds. The
best-known fossil locality in this general region is the classic
Owl Creek locality 7 in Tippah County, Mississippi, often re-
ferred to in the literature as Ripley, Mississippi. (See sketch
map, Fig. 1.)
A sketch map has been inserted on page 77 to show the
location of Coon Creek and Owl Creek and to give in a
general way the areal geology in the region about these
localities. Big Cut and Coffee Landing, two other impor-
tant localities in the Cretaceous Geology of Tennessee are
shown on this map. The information given on the map south
of the Tennessee-Mississippi line has been furnished by Dr.
L. W. Stephenson of the United States Geological Survey.
The Coon Creek horizon is stratigraphically near the base
of the Eipley formation and in the Exogyra costata zone.
«Idem., p. 24.
6 Safford, J. M., Geology of Tennessee, 1869, p. 416.
7 Conrad, T. A., Jowr. Acad. Nat. 8ci., Philadelphia, 1858, vol. iii,
2d ser., pp. 323-336.
Conrad, T. A., Jour. Acad. Nat. Sci., Philadelphia, 1860, vol. iv,
2d ser., pp. 275-298.
Stephenson, L. W., U. S. Geological Survey, 1914, Prof. Paper 81,
p. 24, table 2.
B. Wade
7'7
The Selma-Eipley contact is well established at Blue Cut on
the Mobile and Ohio Eailroad at the state line on the south-
ern extremity of McNairy County. From this point the con-
FIG. 1. Map showing the areal geology of a portion of Tennessee
and Mississippi.
1, McNairy Sand Member; 2, Ripley Formation; 3, Selma Chalk;
4, Eutaw; 5, Tuscaloosa.
tact may be readily traced both by lithological and faunal
relations to Coon Creek. It is thus evident that the Coon
Creek horizon lies just above the Selma chalk and at the
base of the Eipley. The Coon Creek horizon is thus strati-
78 Upper Cretaceous Fauna from Tennessee [276
graphically lower than that along Owl Creek in Mississippi.
At the latter locality the fossiliferous horizon is in the upper-
most beds of the Eipley and is directly overlain by Eocene
limestone.8 Below the Owl Creek beds is the southern equiv-
alent of the McNairy sand member of the Ripley formation.9
The McNairy sand member,, together with about 100 feet
of sparsely fossiliferous, ferruginous Ripley clay, lie strati-
graphically higher than the Coon Creek horizon and are
exposed to the west of it. (For cartographic relations of the
two localities see sketch map in Fig. 1.) Thus, it is quite
evident that the Coon Creek fauna is older than the Owl
Creek fauna.
DESCRIPTION OF THE LOCALITY AND CHARACTER OF THE
SEDIMENT
A thickness of more than thirty feet of the fossil-bearing
beds is exposed along the banks of Coon Creek. For one-third
mile this stream flows in a narrow V-shaped channel from
six to fifteen feet deep which has been cut out during the
last twenty years. The stream has a steep gradient and its
channel is deepened by every heavy rain. The channel fills
quickly after a thundershower and its sides are kept freshly
scoured by the rushing water. White shells of Crassatellites,
Cucullaea, Cyprimeria, Gryphaea, Ostrea, Drilluta, Lunatia,
Baculites, etc., project out of the dark greyish blue matrix
and glitter in the clear water and the sunshine. In general
aspect the exposure bears a striking resemblance to certain
Tertiary beds. In broad physiographic relations, character of
the matrix and whiteness of the shells, the Coon Creek locality
resembles the well-known Upper Cretaceous exposure of
Brightseat, Maryland. This locality is two miles east of Dis-
trict Line and has yielded the most prolific Upper Cretaceous
8 Harris, G. D., The Midway Stage, Bull. Amer. Pal, vol. 4, no. 4,
1896, p. 24.
'Stephenson, L. W., Paper given before the Paleontological So-
ciety of America, December 29, 1916.
Lowe, E. N., Geology of Mississippi, Bull 12, 1915, p. 62.
277] B. Wade 79
fauna of Maryland. The shells, notably the bivalves, are
probably more abundant at Brightseat, but not so well pre-
served as they are at the Tennessee locality. The sediments
containing the Coon Creek fauna are dark bluish green and
gray clayey sands. The sand is of medium fineness and con-
sists of angular and rounded grains of quartz as the major con-
stituent, with glauconite, small flakes of mica, and shell frag-
ments as minor constituents. Pieces of lignitic wood and
small nodular masses of pyrite are common but not abundant.
All of the above elastics are cemented together with a fine
calcareous material, forming a compact impervious mass
which varies locally in arenaceous and argillaceous content.
There is locally sufficient lime for the matrix to become indu-
rated into a very hard, impure and concretionary limestone.
When this marl is thoroughly weathered the shells are re-
moved leaving casts in a matrix which becomes yellowish
brown in color, due to the oxidation of the glauconite and
other ferruginous constituents. Dr. Paul C. Bowers, Chief
Chemist for the Tennessee Geological Survey, has made a
careful quantitative analysis of this marl and reports the
following results :
Si02 65.30
AloO3 8.56
Fe203 3.72
FeO 1.72
MnO 44
CaO 7.10
: 70
ff\ 2-42
P 0 trace
2 5
FeS2 45
C02 5.15
H20 5.45
Carbon 09
Total . ..101.00
80 Upper Cretaceous Fauna from Tennessee [278
HISTORICAL SKETCH
The well-preserved fossils of the Eipley formation attracted
the attention of the early geologists and impressed them very
much. In 1856 Conrad X1 described fifty-six new species from
Owl Creek and made the following observations about the
fauna :
"The Cretaceous strata of Mississippi have long been ob-
served and partially noted by geologists and the lamented
Professor Tuomey has described a number of their fossil con-
tents. I now introduce quite a distinct group of shells, which
are imbedded in a different matrix compared with the preva-
lent cretaceous marls, green sands and limestones. The dis-
covery of these beautiful organic remains is due to the inde-
fatigable exertions of Dr. W. Spillman, of Columbus, who
has forwarded a collection of specimens more or less perfect,
consisting of nearly sixty species, all of which appear to be
unpublished except Scaphites conradi. The appearance of
these shells is like that of eocene species which have merely
lost their animal matter, and in this respect are very unlike
the condition of similar genera in the contiguous rocks of the
same era. The fossils are imbedded in a sandy marl of a
dark gray color, the principal constituents of which are fine
scales of mica and grains of quartz mixed with fragments of
small shells; and though some of the very thin species are
distorted, the stronger retain their original shapes and are
generally very perfect. Species of Crassatetta, Nucula and
Meretrix have the valves united as in life, as well as a few of
the extremely thin Inocerami, though the latter are more or
less distorted by pressure. The numerical proportion of
species of Cephala and Acephala is nearly equal. The external
sculpture of all is as sharply defined as in existing species.
Besides Scaphites and Baculites, there is only one shell in the
collection which resembles a species of the green sand or lime-
11 Conrad, T. A., Jour. Acad. Nat. 8oi., Philadelphia, 2d ser., vol.
iii, pp. 323-336.
279] B. Wade 81
stone, and it is quite distinct. The rare genus Pulvinites is
herein for the first time introduced as an American form.
The analogous species, as well as that of Gervillia, occur in
the Baculite limestone of France and Normandy, which I
believe is referred by d'Orbigny to his Senonian Stage, the
same in which he included the Cretaceous fossils of North
America.
" It is interesting to find bivalves of so remote an era in
sufficient preservation to exhibit generic characters as clearly
defined as they are in living shells. In this condition are
the hinges of Gervillia, Pulvinites, Ctenoides and Cardium.
Here are also specimens of Baculites and Scaphites which
exhibit the interior divested of all extraneous matter, and
delight the eye with exquisite curves of the foliated septa,
whilst the shells glow with brilliant iridescent tints.
" This beautiful series of Cretaceous forms seems to be very
limited in geographical distribution, so far as our present
knowledge extends. It is probably unknown as yet beyond
the limits of Tippah County, which borders on Tennessee.
No account has been given of such a group by the State
Geologists of Tennessee or Alabama. Dr. Spillman informs
me, ' The fossils you have now under examination were found
in the bluffs of Owl Creek, three miles north of the town of
Ripley,' and he concurs in opinion with me that they might
properly be named the ' Ripley group.' He also remarks that
Ammonites placenta occurs in it with the shell preserved, and
that in connection with the Ripley group, or in the same
locality, are ' Exogyra costata, Gryphaea mutabilis, Ostrea
plumosa, Natica petrosa, Nautilus DeKayi, etc., with the shells
more or less preserved, in an argillo-calcreous marl/ but none
of these species are contained in his collections sent me from
Tippah County/'— Conrad, 1858.
After this announcement of the discovery of well preserved
Cretaceous fossils in northern Mississippi was made by Con-
rad, Safford collected a few Ripley fossils from near Purdy,
Tennessee and Tuomey made a large collection of unusually
well preserved shells at Eufaula, Alabama, from the same
6
82 Upper Cretaceous Fauna, from Tennessee [280
horizon as Owl Creek. These collections were sent to Conrad
and Gabb for study and their contributions appeared in 1860
in Volume IV of the Journal of the Philadelphia Academy of
Natural Sciences. In this volume Conrad described fifty-four
additional new species and Gabb four new species collected
from northern Mississippi, Alabama and Tennessee. Since
the work of these men, very little has been done on this un-
usually prolific fauna. Geologists have often visited Owl
Creek and collections have been made but nothing has been
published on the systematic paleontology except for minor
contributions.12 The most recent check list of the Eipley
collections in the National Museum from this region is that
published by Stephenson in 1914.13
STATE OF PRESERVATION OF FOSSILS
A comparison of specimens from the Coon Creek collection
with forms from Owl Creek in the National Museum shows
that the shells from the former locality include many small
and fragile individuals, and that many individuals present
delicate shell parts, internal and external markings not so
well defined, or entirely absent in the Tippah County Speci-
mens. The hinge areas, muscle scars, buttresses, pallial lines
and external sculpture are as sharp and as well defined in
such genera as Cucullaea, Glycymeris, Crassatellites, Nucula,
Cardium, Trigonia, Paranomia, etc., as in the shells of Ter-
tiary and Eecent bivalves. Even the ligaments are occasion-
ally preserved and in their natural positions in attached
valves of Cardium n. sp. Cyprimeria n. sp. and Leptosolen
biplicata Conrad. Many of the Gastropoda, including species
of such genera as Liopeplum, Gyrodes, Ptychosyca, Voluto-
morpha, Pugnellus, etc., are brilliantly glazed. The shells of
Eutrephoceras, Baculites, Scaphites, and Turrilites are well
12 Ball, 1890, Trans. Wagner Free Inst. Sci., Philadelphia, vol. iii,
pt. 1, p. 73.
Ball, 1907, Smiths. Misc. Coll., vol. iv, pt. 1, pp. 1-23.
"'Stephenson, L. W., loc. cit., p. 24, tables 1-9, 1914.
281] B. Wade 83
preserved and abundant but in many cases have been crushed
by the weight of the superincumbent sediments. The proto-
conchs are well defined and in a perfect state of preservation
on many of the Gastropoda, especially such genera as Laxi-
spira, Volutod&rma, Paladmete, Thylacus and many others.
The protoconch is present and sharply differentiated in a
new species of Teinostama which is strikingly like the Mio-
cene form Teinostoma nana (Lea). The adult itself is only
a little more than 1 mm. in its greatest dimension, yet the
shell and protoconch are both brilliantly glazed and look as
fresh as if they were Eecent. The small and fragile Scapho-
pod Cadulus obnutus (Conrad) is abundant and perfectly
preserved. Such over-specialized and projecting shell parts
as the anterior calcareous tube and the fringing tubules of the
genus Clavagella, and the spinose and flaring outer lips of
such genera as Anchura, Aporrhais, Volutoderma, etc., occur
unbroken. Fragments of non-lignitized and non-petrified
wood are common arid resemble Eecent wood in state of pre-
servation as shown by weight, color and woody fiber.
The occurrence of so many perfect shells in unconsoli-
dated sediments as old as the Cretaceous is exceedingly rare.
Although these fossils have retained their original charac-
ters and shell material many of them are soft and fragile so
that some care is necessary in collecting and preparing them.
They are easily removed from the strata with part of the
matrix attached. This serves to protect the specimens in
packing and shipping. When the collected material dries the
sandy matrix may be readily cleared away, leaving most of
the shells hard and fairly strong. The weaker specimens can
be made harder and sufficiently strengthened to withstand
handling and the effects of the atmosphere by a method of
preparing which is used here in the Geological Laboratory.
After all foreign matter has been removed from the shells
they are soaked about four minutes in paraffin heated to the
boiling point. The hot wax permeates the shell walls and
reinforces them. The shells are darkened slightly by the wax
but otherwise the method is altogether satisfactory.
84 Upper Cretaceous Fauna from Tennessee [282
At both the Owl Creek (Miss.) and Brightseat (Md.) lo-
calities the fossil beds occur directly below the Cretaceous-
Eocene contact. This contact represents a long interval of
erosion during which the shell beds were at, or very near, the
surface and were probably subjected to the action of circu-
lating meteoric waters which had a disintegrating effect on
the shells. The abundant springs at this horizon show that
during late Pleistocene and Eecent times this uncomformable
Cretaceous-Eocene contact has furnished an easy channel for
ground waters which have attacked the unpetrified shells.
At Coon Creek, on the other hand, the conditions are some-
what different. There is no overlying uncomformable contact
dircetly above the fossil beds but instead there is a great
thickness of overlying impervious Eipley clays. The shells
were sealed up by the Upper Cretaceous sea in compact, cal-
careous sandy sediments and have been, it seems unaffected
by circulating ground waters until the dawn of the present
physiographic conditions. Even now these beds are so imper-
vious that the ground water does not penetrate them, as is
shown by the fact that well-drillers have reported the strata
perfectly dry. The character of the matrix at the three locali-
ties is essentially the same, so that it seems reasonable to
assume that the Coon Creek shells are well preserved because
they have been protected from circulating ground waters the
action of which is so evident in most Cretaceous strata.
OBSERVATIONS ON THE FAUNA
The Coon Creek fauna is both prolific and varied. Four
days collecting at this locality yielded, according to preli-
minary determinations a fauna of 134 genera and 269 species,
and further collecting has materially increased this number.
The study is yet incomplete and some of the determinations
are merely tentative but the following generalizations may be
made. In the 134 genera already recognized there are, exclu-
sive of the Mollusca, three genera of Vertebrata of the Class
Pisces; 5 of Arthropoda of the Class Eucrustacea; 9 genera
283] B. Wade 85
of Molluscoidea of the Class Bryozoa; 1 genus of Echinoder-
mata of the Class Echinoidea ; 2 of Vermes ; and 1 of Coelen-
terata of the Class Anthozoa. The Mollusca, however, are by
far the most abundant. In this group there are 49 genera
and 110 species of Pelecypoda; 2 genera and 3 species of
Scaphapoda; 60 genera and 120 species of Gastropoda; 4
genera and 7 species of Cephalopoda.
It has been estimated that the Eecent east coast Molluscan
fauna of the Middle Atlantic States includes more than 500
species, and there is no reason to suppose that the Upper Cre-
taceous faunas were materially less prolific. On the contrary,
the seas were warmer and conditions more favorable to mollus-
can life, so that probably not more than one-half the entire
fauna has been discovered.
The Coon Creek fauna flourished near the head of the
Mississippi Embayment and in about the same latitude as the
Middle Atlantic States. It was probably in the same general
climatic zone of the Cretaceous, so that any estimate of the
east coast fauna should hold for the northern part of the
Mississippi Embayment as well. The evidence afforded by
the Coon Creek material shows that the above estimate is not
overdrawn but probably conservative. The extent of the
undescribed fauna is indicated by the fact that four days col-
lecting at Coon Creek has yielded in the Mollusca alone over
100 new species, three new subgenera and eight new genera.
The families and genera with the number of species in each
are as follows (a preliminary list made May, 1916) :
CLASS PELECYPODA
Order Prionodesmacea
Nfcculidae. Nucula 3 species
Ledidae. Leda 2 species
Yoldia 1 species
Parallelodontidae. Nemodon 3 species
Cucullaea 4 species
Arcidae. Area 4 species
Glycymeris 2 species
Axinea 1 species
Postligata 1 species
86 Upper Cretaceous Fauna, from Tennessee [284
Perniidae. Inoceramus 3 species
Gervilliopsis 1 species
Pteriidae. Pteria 2 species
Ostreidae. Ostrea 8 species
Exogyra 1 species
Pycnodonte 1 species
Gryphaeostrea 1 species
Trigoniidae. Trigonia 2 species
Pectinidae. Pecten 4 species
Limidae. Lima 2 species
Anomiidae. Paranomia 3 species
Anomia 3 species
Pulvinites 1 species
Mytilidae. Modiolus i species
Lithophaga 3 species
Crenella 2 species
Dreisseniidae. Dreissena 1 species
Order Anomalodesmacea
Anatinidae. Periplomya 1 species
Anatimya 1 species
Corimya 1 species
Clavagellidae. Clavagella 2 species
Poromyacidae. Liopistha 3 species
Order Teleodesmacea
Pleurophoridae. Veniella 1 species
Crassatellitidae. Crassatellites 4 species
Astartidae. Vetericardia 1 species
Diplodontidae. Tenea 3 species
Cardiidae. Ca'rdium 4 species
Veneridae. Cyclina 2 species
Meretrix 4 species
Legumen 2 species
Cyprimeria 1 species
Tellinidae. Linearia 2 species
Solenidae. Leptosolen 1 species
Mactridae. Spisula 1 species
Corbulidae. Corbula 4 species
Saxicavidae. Panope 2 species
Pholadidae. Pholidea 2 species
Teredinidae. Teredo 4 species.14
CLASS SCAPHOPODA
Dentaliidae. Dentalium 2 species
Siphonodentaliidae. Cadulus 1 species
14 Besides the above named genera there are probably two others in
the collection whose generic relations have not been determined on
account of fragmentary material.
285] B. Wade 87
CLASS GASTROPODA
Order Opisthobranchiata
Suborder Tectibranchiata
Acteonidae. Acteon 5 species
Tornatella 2 species
Ringiculidae. Ringicula 1 species
Scaphandridate. Cylichna 1 species.
Order Ctenobranchiata
Suborder Toxoglossa
Cancellariidae. Paladmete 3 species
Mataxa 1 species
Turritidae. Turris 1 species
Surcula 6 species
Volutidae. Volutoderma 3 species
Volutomorpha 5 species
Tectaplica 1 species
Liopeplum 1 species
Drilluta : 2 species
Ptychosyca 2 species
Mitridae. Mitra 1 species
Vasidae. Xancus 3 species
Fusidae. Fusus 2 species
Subgenus Anomalofusus 1 species
Ornopsis 2 species
Fasciolaridae. Piestochilus 1 species
Odontof usus 3 species
Thaisidae. Sargana 2 species
Busyconidae. Busycon 1 species
Pyropsis 3 species
Pyrif usus 3 species
Buccinidae. Hemifusus 1 species
Hydrotribulus 2 species
Nyctilochidae. Tritonium 1 species
Columbellariidae. Columbellina 1 species
Strombidae. Pugnellus 1 species
Rimella 1 species
Aporrhaidae. Aporrhais 6 species
Anchura 2 species
Suborder Streptodonta
Scalidae. Pseudomelania 1 species
Vermetidae. Laxispira 1 species
Turritellidae. Turritella 8 species
Naticidae. Gyrodes 3 species
Lunatia 2 species
Capulidae. Thylacus 1 species
Littorinidae. Littorina .1 species
88 Upper Cretaceous Fauna from Tennessee [286
Order Aspidobranchiata
Eulimidae. Leiostraca 1 species
Euomphalidae. Hippocampoides 1 species
Turbinidae. Schizobasis 1 species
Trochidae. Solariella 2 species
Umboniidae. Teinostoma 1 species
Delphinulidae. Urceoabrum 1 species
Liotai 3 species.15
CLASS CEPHALOPODA
Order Nautiloidea
Nautilidae. Eutrophoceras 1 species
Order Ammonoidea
Lytoceratidae. Baculites 3 species
Turrilites 1 species
Cosmoceratidae. Genus Scaphites 1 species
Probably the most significant fact revealed by the above
list is that the number of univalve species is greater than the
number of bivalve species. However, all three orders of the
Pelecypoda are well represented. Of the Order Prionodes-
macea the three families represented by the greatest number
of forms are the Arcidae, Ostreidae and Mytilidae. The last
two had their beginning in the Paleozoic. The Arcidae ori-
ginated and suddenly became a prominent group in the latter
part of the Mesozoic and developed into very great import-
ance in the Tertiary. Each of these three families is repre-
sented by four genera at Coon Creek. Among the Anomalo-
desmacea there are three families and five genera. The
Teleodesmacea are well represented. Of this order probably
the individuals of the families Cardiidae, Veneridae, and
Corbulidae are most abundant. A comparison of the above
list with lists from the East Coast Cretaceous shows that the
bivalves are relatively less abundant in the Coon Creek hori-
zon than in corresponding horizons in New Jersey and the
Middle Atlantic States. Several genera such as Cuspidaria,
15 Besides the above named genera there are probably thirteen
genera and more than that number of species whose generic relations
have not been determined on account of the fragmentary condition
of the material.
287] B. Wade 89
Myrtaea, Phacoides, Docinia, Tellina, Solyma, etc., are absent
from the present McNairy County collection though it is
probable that further collecting may reveal some of them.
The Scaphopoda are represented by the two families Den-
taliidae and Siphonodentaliidae. The former originated in
the Ordoviciari and are abundantly developed in the Creta-
ceous and Tertiary. They are represented at Coon Creek by
one genus and two species, one of which is very common.
The family Siphonodentaliidae is first found in the Creta-
ceous. At Coon Creek it is abundantly represented by the
minute form Cadulus obnutus (Conrad).
The Gastropoda are the most interesting class in the Coon
Creek fauna. It will be noted from the list given above that
the number of genera and species of the Gastropoda is con-
siderably greater than the number of the Pelecypoda, yet,
probably in every cubic yard of the Coon Creek sediments
the number of bivalve individuals exceeds the univalve indi-
viduals several times. In all the faunas previously reported
from the Cretaceous of Eastern United States the bivalve
species are more numerous than the univalve species. This
majority among the latter may be due simply to the fact that
in the Upper Cretaceous seas of those regions the pelecypods
predominated in number of species as well as individuals, or
it may be that a greater number of gastropod species existed
in all the Cretaceous seas but were not preserved sufficiently
to be recovered from the sediments. The chance of preser-
vation of gastropod shells is not as good as it is for pelecy-
pods, first, because the number of individuals per species of
the Gastropoda is rarely ever as great as it is among the
Pelecypoda. Second, the essential constituent of univalve
shells is aragonite, and this mineral is much less stable than
calcite, which is the essential constituent of the majority of
pelecypod forms. Third, a gastropod shell is in greater
danger of being crushed by the pressure of the inclosing
sediments because of lack of support from within the shell.
The body cavity of gaping bivalved shells is almost of neces-
sity filled, while the sediments are intruded less readily
90 Upper Cretaceous Fauna from Tennessee [288
through the aperture in the spiral body cavities of univalves.
The shells thus unsupported within become crushed by super-
incumbent .sediments and are then rapidly disintegrated.
In general, the Tertiary and Eecent faunas of North
America contain a greater number of univalves species and
it may be that about the same proportion existed in all the
Cretaceous faunas. Yet it may be that the faunas, as they
have been reported, represent the natural proportions in
which these animals lived in the Cretaceous sea. It is possible
that the gastropods became diversified in the Cretaceous and
that this diversification took place only in certain provinces,
where environments favored variation. Excavating and ex-
tensive collecting in localities where the shells are especially
well preserved will probably throw some light on this question.
In the order Opisthobranchiata there are three families and
four genera found in the Coon Creek collection. Of these
the family Acteonidae, which had its beginning in the Devo-
nian and gained great prominence in the Mesozoic is repre-
sented by the genera Act eon and Tornatella. The former in-
cludes probably five species and the latter two. The families
Ringiculidae and Scaphandridae are each represented by one
genus and one species.
The order Ctenobranchiata is most abundant and is repre-
sented by 48 genera, 30 of which belong to the suborder
Toxoglossa and 18 -to the suborder Streptodonta. Among
the Toxoglossa the family Cancellariidae is first differenti-
ated in the Upper Cretaceous. It appears suddenly much
diversified in that period and attains its maximum distribu-
tion in the late Tertiary and Eecent. This family is repre-
sented at Coon Creek by two genera. The most prolific of
these is Paladmete, a genus first recognized and described by
Dr. Julia A. Gardner who has recently monographed the
Upper Cretaceous Mollusca of Maryland.16 The type spe-
cies of Paladmete is very abundant in Maryland and north-
16 Gardner, J. A., Md. Geol. Survey, Upper Cretaceous vol., Text,
p. 412, 1916.
289] B. Wade 91
ern Mississippi. The genus is represented by three species at
Coon Creek. Mataxa is a form regarded by me as a new
genus and is referred to the Cancellariidae. A species of
Mataxa has been described from South India by Stoliczka 1T
and asigned to the genus Narona of the Cancellariidae. A
study of Stoliczka's description and figures together with
perfect specimens from Coon Creek shows that these species
belong to the same genus which is evidently not Narona, so
it seems advisable to assign these two forms to Mataxa as a
new genus in the Cancellariidae. The Turritidae is another
family which is represented in the Cretaceous by several
forms and is not found in earlier strata. There are two gen-
era of this family at Coon Creek, Turris, and Surcula. The
latter is especially varied, and includes probably six species.
The Volutidae is the most prolific and interesting family
of the Coon Creek collection. It contains six genera and
sixteen species, nearly all of which are represented by abun-
dant, well characterized and perfectly preserved shells. The
remarkable efflorescence of the Volutes in the Upper Creta-
ceous has been discussed by Dall who mongraphed the Volu-
tidae in 1890 18 and in 1907.19 The Coon Creek Volutes
include the genera Volutomorpha, Volutoderma, Ptychosyca,
Liopeplum, two new genera, Drilluta and Tectapl^ca and two
species of a form whose generic relations have not been fully
determined. The genus Ptychosyca was named and described
by Gabb in 1876.20 Dall did not consider this genus a
Volute in his monograph of this family, but two species re-
presented by well preserved material in the McNairy County
collection reveal new characters that indicate that this form
17 Stoliczka, F., Geol. Surv. of India, Cret. Faunas of South India,
vol. ii, p. 166, pi. xiii, figs. 15, 16.
18 Dall, 1890, Trans. Wagner Free Inst. Sci., Philadelphia, vol. iii,
pt. 1, p. 72.
19 Dall, 1907, Smiths. Misc. Coll., vol. iv, pt. 1, pp. 1-23.
20 Gabb, W. M., Proc. Acad. Nat. Sci., Philadelphia, 1876, p. 295,
pi. 17, figs. 2-4.
92 Upper Cretaceous Fauna from Tennessee [290
is quite probably a member of the Volutidae and near the
genus Liopeplum.
The Mitridae and Vasidae are each represented by one
genus. The genus Xancus of the Vasidae is represented by
three species which are well characterized by the manner of
excavation of inner lip and number of columellar folds. This
genus is well represented in the Upper Cretaceous and was
first identified from the Cretaceous quite recently by Dr.
Gardner.21 The Fusidae which appeared in the Jurassic and
are widely developed in the Tertiary and Recent are repre-
sented at Coon Creek, besides the genus Fusus, by a form
which is considered of the rank of a subgenus under Fusus
and given the name Anomalofusus as a new subgenus. The
Fusidae are further represented by two very common well
characterized species for which the new genus Ornopsis has
been proposed. The family Fasciolariidae embraces the gen-
era Piestochilus and Odontofusus, the latter being repre-
sented by three species which are very closely related. The
well-characterized genus Sargana, of the Thaisidae, is repre-
sented at Coon Creek by two species, one of which is very
abundant and perfectly preserved.
The family Busyconidae is interesting in that it appears
rather suddenly in the Cretaceous with numerous, diversified
representatives. At Coon Creek it is represented by three
genera and seven species. These genera are Busycon, Pyrop-
sis and Pyrifusus.
Pyropsis and Pyrifusus are very abundant in the Creta-
ceous and have a world-wide distribution. Busycon, very
commonly known as Fulgur, is rarely found in the strict
sense in the Cretaceous. This extension of the range of this
common East Coast Tertiary and Recent form is of particular
interest. It is represented in the present Coon Creek col-
lection by a single well preserved specimen, a description
of which has been prepared for publication. This specimen,
aside from the absence of the protoconch is perfect and pre-
21 Gardner, J. A., loo. cit., p. 434.
291] B. Wade 93
sents generic characters which cannot be mistaken. The
species bears a striking resemblance to some of the medium-
sized late Tertiary and Eecent species. All the typical Ful-
gurs previously known have been limited to the Tertiary and
Eecent of the Atlantic States. The Eocene forms are small,
rather thin-shelled species, so it has been considered that the
genus evolved during that period. The living Fulgurs have
been very extensively studied and the life history carefully
worked out. The limited geographic range has been ex-
plained in a large measure by the fact that the animal is
deprived of an active free-swimming larval stage by the loss
of the velum before the young form emerges from the egg-
capsule. This same fact might well be cited to explain the
very limited distribution of Busy con in the Cretaceous. One
of the earliest Tertiary species (described and referred to
genus Fulgur by Harris22), occurs in the Midway group of
the Eocene about 30 miles west of Coon Creek.
In the family Buccinidae there is a species represented by
large elegant specimens which seems to belong to a well-
defined generic group for which the name Hydrotribulus has
been proposed. Species of this genus have been recognized
from Brightseat, Maryland and Owl Creek, Mississippi. A
study of the description of a species, Tudicla monheimi
(Muller) Holzapfel23 from the Aachen beds of western Ger-
many shows that the European form belongs to the same
genus as the American forms and it seems advisable to pro-
pose a new genus for this group. Hemifusus is another
genus that occurs among the Coon Creek Buccinidae and is
a form which has never before been reported from the Cre-
taceous of Eastern United States.
In the family Nyctilochidae there is a single genus Tri-
tonium. The family Columbellariidae is represented by a
22 Harris, G. D., Bull. Amer. Pal, 1896, vol. i, no. 4, p. 96, pi. 9,
fig. 13.
23 Holzapfel, E. Pelaeontographica, 1888, Band xxxiv, pag. 106,
Taf. xi, figs. 4-7.
94 Upper Cretaceous Fauna from Tennessee [292
single small individual which has been assigned to the genus
Columbellina, a group not previously reported from the Cre-
taceous of North America. One species of the genus Pugnel-
lus of the Strombidae is very common in the Coon Creek beds.
A species of Rimella of the same family is represented by one
specimen. The family Aporrhaidae is prolific, its two gen-
era Aporrhais and Anchura include probably nine species.
In the suborder Streptodonta the families Scalidae, Ceri-
thiidae, Trichotropidae, Vermetidae, and Turritellidae are
each represented by a single genus. In the genus Turritella
there are probably 8 species. Both Lunatia and Gyrodes of
the Naticidae are common. The individuals of one species
of Lunatia are probably more abundant than any other gas-
tropod species. The family Capulidae is represented by
small, fragile individuals of a single species of the genus
Thylacus which was described from Owl Creek by Conrad in
I860.24 The individuals of this species are small and very
fragile, yet they are abundant and perfectly preserved in
their natural habitat. They occur in place fitting snugly to
the columellar walls in the body cavities of larger gastropods.
They have the internal muscular impression produced and
leaving the wall of the shell at the anterior extremities, and
lack the calcareous foot-plate characteristic of the genus
Hipponix of this family. The family Littoriniidae is repre-
sented by the genus Littorina which is common in the Ter-
tiary and Eecent of the East Coast and Gulf regions, but up
to the present has not been reported from the Cretaceous of
these regions. f-
The genus Leiostraca of the family Eulimidae and order
Aspidobranchiata is represented by abundant but often poor-
ly preserved specimens, due to the fragility of the shell.
The family Euomphalidae which is variously represented in
both the Paleozoic and Mesozoic, includes a new genus Hip-
pocampoides. This is a much depressed form with a pro-
24 Conrad, T. A., Jour. Acad. Nat. Sci., Philadelphia, 1860, vol. iv,
2d ser., p. 290, pi. 46, fig. 22.
293] B. Wade 95
duced keel and angular shoulder. Most of the specimens in
this family that have been described from the Cretaceous of
the Eastern United States have been referred to the genus
Straparollus, and in most cases these specimens are casts
and do not show any shell characters, so that it is possible
that some of these casts belong to Hippocafrnpoides. The
family Turbinidae is herein reported from the Cretaceous
of Eastern North America for the first time. This family
is abundantly developed in the Paleozoic and is common in
the Eecent. The new genus Schizobasis which is character-
ized by a very unique, flattened notch-like anterior canal
is referred after some hesitation to the family Turbinidae.
The families Trochidae and Umboniidae which have repre-
sentatives from the Silurian to the Recent are each repre-
sented by a genus in the Coon Creek fauna. These genera
are Solariella and Teinostoma respectively and are both
herein reported for the first time from the Cretaceous of
North America. Another genus hitherto unknown in Ameri-
can Cretaceous is Liotia of the family Delphinulidae and in
this family occurs another very abundant form at Coon Creek
for which the genus Urceolabrum is here proposed. This
seems to be a well denned generic group near Liotia but dis-
tinctly different from typical Liotiae occurring in the same
strata. Besides the Coon Creek species Urceolabrum includes
an undescribed species from Aufaula, Alabama, and another
from the Aachen beds 25 of Vaals, Germany.
In addition to the above cited genera there are probably
as many as thirteen genera of Gastropoda, including that
many and more species whose generic and .family relations
cannot be assigned with assurance on account of their frag-
mentary character.
The point of greatest interest in the Coon Creek gastro-
pods is the occurrence of eight new genera and one new pub-
genus, many of which are represented by more than one spe-
25 Holzapfel, E., Palaeontographica, Band xxxiv, p. 170, Taf . xviii,
figs. 3-7.
96 Upper Cretaceous Fauna from Tennessee [294
cies and also from more than one locality, as is shown in the
literature by described species which have been questionably
assigned generically. The genera Solariella, Liotia, Teinos-
toma, and Columbellina have not been previously reported
from North American Cretaceous, and Hemifusus and Lit-
torina have not been previously reported from the Cretaceous
of the Eastern United States. A typical Busycon or Fulgur 2G
is for the first time found in Cretaceous sediments. The
Volutes are profusely developed, being represented by six
genera and eighteen species.
Among the Cephalopods both the nautiloids and ammonoid
orders are present and represented by abundant large well-
preserved specimens. It is interesting to find the remains
of the most primitive order of Cephalopoda which ranges
from the Paleozoic to the Eecent associated with abundant
remains of the most highly complex and degenerate cephalo-
pods, indicating that both thrived under the same conditions,
yet the latter became extinct and the former continues to
live. The family Nautilidae is represented by one species
of the genus Eutrephocems. The most common cephalopods
at Coon Creek are the Baculites and Turrilites of the family
Lytoceratidae. Baculites is profusely developed and proba-
bly includes three species. The Cosmoceratidae include one
species of the genus Scaphites.
Conditions must have been especially favorable for mollus-
can life in the Upper Cretaceous sea in which the members
of the Coon Creek assemblage grew. A glance at a tray of
specimens impressed the observer- with the fact that the shells
are the remains. of once-flourishing animals. Very many of
the shells are thick, stout and of imposing dimensions. Evi-
dently they belonged to robust, healthy and well-fed organ-
isms. The bivalve with the greatest lateral dimensions is a
species of Inoceramus which was probably 15 inches in maxi-
mum diameter. One species of Cardium is 5 inches in length
26 Bruce Wade, 1917, Am. Jour. Sci., vol. xliii, no. 256, p. 293,
figs. 1 and 2.
295] B. Wade 97
and a Cyprimeria is 4^/2 inches. Exogyra costata and Gry-
phaea vesicularis occur in their typical massiveness. The
shells of Cucullaea, Crassatellites and Veniella are very
abundant and evidently belonged to three very thrifty groups
of Mollusca which lived under conditions especially suited to
the secreting of calcium carbonate. The afflorescence of the
Volutidae in the Upper Cretaceous has already been empha-
sized. All the species of this family are above medium size
and many of them are very large. Perfect specimens of
Volutoderma in the collection attain an altitude of half a
foot. There are broken specimens which when perfect must
have been almost a foot long. Volutomorpha is probably the
giant of the Cretaceous gastropods. There is a fragmenl
of several whorls of the spire of one species of Volutomorpha
in the collection which would probably be 18 inches in length
were the specimen complete. The genus Ptychosyca is large
and inornate while the genus Drilluta is elongate and elabo-
rately sculptored. The shells of Pugnellus and Gyrodes seem
to be relics of once prosperous organisms which saw no
hardships in life. Lwpeplum, Lunatia, Xancus, Hydrotri-
~bulus, Ornopsis, etc., though less in dimensions than some of
the above forms, evidently grew in very favorable environ-
ments. Species of such genera as Columbellina, Solariella,
Act eon, Cerithium, etc., are much smaller in size, yet their
shells are thick and stout, and no doubt grew where condi-
tions were favorable for secreting calcium carbonate. The
bivalves also show various ranges in size of thick, stout shells.
The Cephalopoda were the largest of the Coon Creek Mol-
lusca. The genus Eutrephoceras is abundantly represented
by large thick-shelled cavernous individuals more than six
inches in diameter. One species of Baculites is very abundant
and large. Although no complete, large individuals have been
recovered from the matrix, there are several large pieces of
shells and body chambers in the collection from 6 to 18
inches long and restorations of these show that some indi-
viduals were five feet in length. It should be noted here that
while most of the Upper Cretaceous molluscs had thick stout
7
98 Upper Cretaceous Fauna from Tennessee [296
shells with coarse, vigorous ornamentation, yet many pos-
sessed small, delicate, fragile and. thin shells, but have never-
theless been preserved perfectly to the present. Individuals
of species of Leda, Cadulus and Teinostoma are smaller than
a wheat gain. Yoldia, Anatimya, Tenea, Liopistha, Leio-
straca are represented by delicate and fragile individuals.
One species of Crenella is thinner than paper yet it is ele-
gantly sculptured.
It is impossible to postulate with assurance the depth of
the water in which the Coon Creek fauna lived. Such fami-
lies as the Pernidae, Volutidae and Lytoceratidae, which are
very prominent in the assemblage, are usually regarded as
dwellers in the open sea at a depth of about 50 fathoms.
Yet the Nuculas, Corbulas, and Naticoids, etc., are for the
most part dwellers in shallow water near shore. Lobsters
and true crabs lived in great abundance in the Eipley sea as
is shown by the remains of these forms which are very com-
mon in the Coon Creek sediments. There are probably five
genera of the Eucrustacea, among which is a large crab about
seven inches across from .right to left and whose modern
affinities live in the intertidal zone of the seas. No fora-
miniefra have been found. Only two very small individuals
of two species of corals have been recovered. These last two
facts, together with the very abundant crab remains indicate
very near-shore or intertidal waters as the habitat of the
Coon Creek fauna.
As regards the evidence furnished by the sediments there
is no well-marked cross-bedding which would result from
strong current action. However, the very presence of clastic
material such as sand and clay require currents to account
for transportation, and shifting of these currents to explain
the intermingling of these materials. The great abundance
of pelecypods which are organisms that feed for the most
part on plankton is indicative of waters disturbed by cur-
rents, instead of very calm seas, for plankton occurs mostly
in water that is agitated by currents. No pebbles whatever
have been observed in the sediments of the Coon Creek
297]
B. Wade
99
horizon, wood fragments are, however, common. The totality
of the evidence seems to indicate that the Coon Creek fauna
lived in the agitated waters near the coast of .a low-lying
land mass.
A study of the distribution and variation of the faunas
with reference to the character of the sediments in the Rip-
ley formation of northern Mississippi and southern Tennes-
see shows that the areas so favorable to molluscan life were
a •'.'.*.;.',••'•! •'..',' • \ '..'/ .•••'. '•'..'• ".•.••' •'.''..' • . . '• .. • '.• • .' '. . • .'
W MUv**y Group.
T Owl C'rtti ffcriiiT, + N,,tA'rn fflt*
17 Mc/fitty Sin<t Mimic,
JHFtiTugin,,** City Ho*U°n
I Stlmi CAt2t
Big Cut
S.ln,.r -
FIG. 2. Section of Upper Cretaceous deposits of McNairy County,
Tennessee.
quite local in extent. The sediments bearing such an abun-
dance of shells are limited both laterally and vertically in the
Ripley strata and do not show a uniform wide range over a
large area as is so commonly true of Paleozoic fossiliferous
beds. (A diagrammatic section SW-NE across the McNairy
County is shown in Fig. 2.) By tracing the Coon Creek
horizons southward the plentiful shells disappear leaving in
some places a very dark non-fossiliferous clay. Near Larton,
McNairy County, the basal Ripley beds are represented by a
glauconitic sand which contains branching remains of the
so-called fucoid Halymenites major Lesq. This thickness of
LOG Upper Cretaceous Fauna, from Tennessee [298
sand extends further southward and at Sand Hill is over-
lain by calcareous sediments containing an unstudied fauna
of probably 50 species. Three miles farther southwest there
are non-fossiliferous gypsifeous clays at the base of the Eipley.
Overlying the variable Coon Creek horizon is a thickness
of ferruginous and micaceous Eipley clays which extends in
a belt across the county. These sediments contain a sparse,
dwarfed fauna of a few pelecypod genera such as Cardium,
Cyprimeria, Pecten, etc., none of which are as much as one-
half inch in maximum diameter. Gastropods, cephalopods
and large massive bivalves such as Exogyra or Gryphaea -are
absent. Evidently conditions were unfavorable for molluscan
life where these deposits were formed. Above this is the non-
fossiliferous McNairy sand, and overlying that is the classic
fossiliferous Owl Creek horizon. Thus the evidence seems
to show that there were local areas where conditions were
very favorable for rapid development of life, while other
regions were not suited to the growth of marine organisms.
There were probably local biological provinces which favored
the development of local faunas. This may be observed in
a comparison of the Owl Creek and Coon Creek faunas. Al-
though these localities are within sixty miles of one another
and in the same formation, the two faunas have a distinctly
different aspect. Very many of the species are different yet
many are identical. There are a number of genera from
each locality not common to the other. At Owl Creek the
percent of bivalve species is greater than that of the uni-
valves, while at Coon Creek the fauna is striking for the
predominance of gastropod species. The Cephalopod SpJie-
nodiscus has not been found at Coon Creek while at Owl
Creek it is represented by two species. As has been stated
above the Owl Creek horizon is stratigraphically above the
Coon Creek beds so there should be some differences in the
faunas due to age but it is a question whether there should
be such a striking difference in assemblages from the same
formation located so near each other if such conditions as
local biological provinces had not existed. It seems reason-
299] B. Wade 101
able to conclude from a study both of the sediments and the
faunas and their distribution that, in this part of the Mis-
sissippi Embayment of the Ripley Sea, there were certain
restricted areas, that were especially favorable for the growth
of Mollusca. These areas were separated from one another
by regions, as the sediments show, not so favorable for marine
life and such regions as served to hinder free migration from
one province to another. In these isolated " places of much
life" variations took place due to biological and physical
conditions. Environmental changes were constantly taking
place due to shift and sinuosity of strand-line and change
in character of sediments. In many provinces the faunas
were destroyed entirely, in places some survived longer and
were dwarfed, favorable places were crowded with great
hordes and here evolutionary processes were most active.27
27 During the past winter, after the above preliminary account of
the Coon Creek fauna was written, the writer has been engaged in a
systematic study of the Gastropoda of this fauna in preparation of a
dissertation to be submitted to the Board of University Studies. A
few days collecting at Coon Creek during the summer of 1916 added
many excellent and interesting specimens to the collection and
the study of this material, together with that assembled in 1915, has
resulted in the recognition of about 75 genera and 140 species of
gastropods alone. About two-thirds of these are new species, as only
about 45 species of univalves were previously known from the Cre-
taceous strata of the Eastern Gulf Region, and of this number only
about 10 had been recognized in the State of Tennessee. It is proba-
ble that the locality is not exhausted as yet, and that further col-
lecting, which is planned for the summer of 1917, will yield a few
additional species of Gastropoda.
102 Tuscaloosa Formation [300
THE OCCURRENCE OF THE TUSCALOOSA FORMATION
AS FAR NORTH AS KENTUCKY1
By BRUCE WADE
The Tuscaloosa formation is the basal member of the Upper
Cretaceous series in the Eastern Gulf Region of the Missis-
sippi Embayment. In Western Alabama and Eastern Mis-
sissippi this formation consists of irregularly bedded sands,
clays, and gravels having an estimated total thickness of 1,000
feet. In Professional Paper 81 of the U. S. Geological Sur-
vey L. W. Stephenson has readjusted the nomenclature of the
Upper Cretaceous in this region and has defined the Tusca-
loosa with reference to the other formations of this series.
, Toward thejntorth the Tuscaloosa deposits become much
• ,thinnef •"&&& We- 'made up almost entirely of conglomerates
,w<hjc.h, contain Httle*sand and clay. Professor E. W. Berry
hgis; made a 'sturdy brf this series and has found evidence in the
fossil plants that the clays, in the basal part of the formation
in the region of maximum thickness, are more ancient than
plant-bearing clays that occur in the conglomerates about
luka, in northeastern Mississippi where the formation becomes
much thinner. He shows that an Upper Cretaceous estuary
existed for a long time in Western Alabama before it trans-
gressed into the northern part of Mississippi and Alabama.
Until recently the Tuscaloosa formation was thought to
thin out entirely in the vicinity of the Tennessee-Alabama
line. In 1913 H. D. Miser mapped the areal geology of the
Waynesboro Quadrangle of Tennessee and found that the Tus-
caloosa was 150 feet 2 thick and extended over a large part of
Wayne County. Subsequent work by the Tennessee Geologi-
1 Published with the permission of Dr. A. H. Purdue, State Geolo-
gist of Tennessee.
2 Miser, H. D., " Economic Geology of the Waynesboro Quadrangle,"
Resources of Tennessee, 1913, vol. iv, no. 3, p. 107.
301] B. Wade 103
cal Survey showed that remnants of the Tuscaloosa gravel
occur in place on the Highland Rim of Tennessee as far
north as the northern Lewis County.3 Farther north, during
the past summer, the writer encountered undescribed occur-
rences of the Tuscaloosa formation which show that the sedi-
ments of this transgressive phase of the Upper Cretaceous
exist in a chain of local outlying areas across the State of
Tennessee and as far^ north as the ridge west of Canton,
Kentucky.
An important link in this chain are the gravels which
occur locally along the Nashville, Chattanooga and St. Louis
Eailroad between McEwen and Tennessee City and capping
the higher hills in this part of Dickson County, Tennessee.
A cut on the railroad about two miles east of McEwen shows,
resting on chert of the St. Louis formation, about 30 feet
of very compact hard white chert gravel which is very typical
of the Tuscaloosa belt across the State. No paleontological
evidence has been obtained from the gravels about McEwen
to determine the age of these deposits, but after a study of
the lithology a swell as the geographic and topographic rela-
tions, the Tuscalocsa age of the McEwen gravels can hardly
be doubted. These gravels are made up of well rounded water
worn pebbles, most of which are one inch or less in diameter,
although many are larger, often ranging up to cobbles six
inches in diameter. Many individuals approach a sphere
in outline and in this respect they differ from the river
gravels which are common in terraces along the Western
Tennessee Valley. In the river gravels of this region the
individuals are often flat, elongated, and subangular. Small
discoidal quartzite pebbles are often conspicuous in the ter-
race conglomerates. The .Tuscaloosa conglomerates consist
for the most part of pebbles and boulders derived from
the Lower Carboniferous cherts which are common in this
part of the Mississippi basin. Water worn sandstone and
3 Wade, Bruce, " Geology of Perry County and Vicinity." Resources
of Tennessee, 1914, vol. iv, no. 4, p. 173.
104 Tuscaloosa Formation [302
iron oxide pebbles have not been observed in the Tusca-
loosa. This is another feature which serves to distinguish
the Upper Cretaceous gravels from the more recent terrace
gravels in this part of the Embayment Region, even though
the latter may rest directly on the former as is frequently the
case in the Western Tennessee Valley.
South of McEwen, as stated above, the isolated Tuscaloosa
gravel areas may be traced along the Highland Rim across
Lewis County into Wayne and Hardin Counties and farther
into Mississippi and Alabama where, they are overlain by
marine Eutaw deposits and consequently paleontologic evi-
dence may be obtained.
The Tuscaloosa extends also north of McEwen. About 3
miles west of Canton in Trigg County, Kentucky, at a point
just east of where the Fulton and Nashville Highway crosses
the divide between the Tennessee and Cumberland Rivers is
an exposure of Upper Cretaceous which has not heretofore
been reported. The locality is about 7 miles each of the
Upper Cretaceous belt as shown by the Geological Map of
Kentucky.4 At this locality the following section may be
observed :
River Terrace, sandy clay and leached soil which
becomes thicker 14 mile to the
west where it contains thick beds
of ferruginous conglomerate. .0 — 12 ft.
Eutaw, red micaceous sand containing
streaks and pellets of white clay
and remains of Halymenites ma-
jor Lesquereux 0 — 10% ft.
Tuscaloosa, well rounded white chert pebbles
and cobbles. The base of the
Tuscaloosa was not exposed here
but Mississippian chert occurs in
place some distance below in the
hollow leading northward +31 ft.
4 Sellier, L. M. " State Geological Map." Kentucky Geological
Survey, 1915.
303]
B. Wade
105
The above section occurs in the top of the divide which
is probably more than 300 feet above the waters of the Ten-
nessee and Cumberland Rivers. This divide is a northern
extension of the Western Highland Rim of Tennessee and it
is probable that further study of the plateau between the
FIG. 1.
Sketch map of the Eastern Gulf area showing the northward
extension of the Tuscaloosa formation from the previously mapped
area in solid black.
1. — Section in Trigg County.
2. — Section in Dickson County.
3. — Section in Lewis County.
4. — Section in Wayne County.
Canton and McEwen localities will reveal isolated occur-
rences of Tuscaloosa that form an almost unbroken chain of
the remnants of this formation from Kentucky across Ten-
nessee into Mississippi and Alabama.
A study of a map 5 of the Upper Cretaceous belt of the
6 Stephenson, L. W.., " Cretaceous Deposits of the Eastern Gulf
Region." U. S. Geological Survey, 1914, Professional Paper 81, map.
106 Tuscaloosa Formation [304
Eastern Gulf Region shows that the Tennessee River flows
from the east into the Cretaceous in northwestern Alabama
and then takes a northerly course just east of the Cretaceous
across Tennessee and Kentucky. The geological map shows
that the wide Tuscaloosa belt in Western Alabama and East-
ern Mississippi disappears entirely just north of where the
Tennessee River flows into the belt, and in the same part of
the state the Eutaw belt becomes abruptly narrow and dis-
appears long before it reaches the northern limit of Tennes-
see. It has been the purpose of the present article to call
attention to the occurrence of both Eutaw and Tuscaloosa
sediments farther north than has been heretofore reported
and to point out that these occurrences show that the Tusca-
loosa formation, though probably not as thick and as wide-
spread as in Western Alabama and Eastern Mississippi, was
at one time an important formation and covered large areas
in Tennessee and Kentucky, and that the Eutaw formation
extended farther east and north of the areas mapped. The
erosion of the Western Tennessee Valley has almost entirely
removed the Tuscaloosa deposits toward the north, and has
likewise removed a large portion of the Eutaw deposits, but
to a less extent than in the case of Tuscaloosa.
The accompanying sketch map shows the formerly known
distribution of the Tuscaloosa in Eastern Mississippi and
Western Alabama and the probable northward extension of
the Tuscaloosa belt as shown by the recent work in this
area.
305] G. E. Dorsey 107
THE HABITAT OF BELEMNITELLA AMERICANA AND
MUCRONATA
By GEO. EDWIN DORSET
The question as to whether or not the almost cosmopolitan
range of certain type fossils is an indication of similar life
conditions over wide areas, or to what extent it may indicate
especially hardy, easily or rapidly adaptable organisms, has
never been tested. Presumably in the case of some organ-
isms cosmopolitanism is attained because of the wide extent
of favorable environments, while in the case of other organ-
isms they are less affected by the environment or more
adaptable to it.
With the idea of ascertaining whether similar conditions
of deposition of the fossiliferous sediments as evidenced by
identical or similar lithology can be correlated with the
occurrence of particular species of wide-ranging fossils, I
have taken the form Belemnitella americana with its Euro-
pean analogue, Belemnitella mucronata, and have searched
the literature .with regard to their occurrence and the char-
acter of the sediments in which they are found. The result
is very interesting and fairly conclusive.
To anticipate these results I have found that in almost
every instance where these types are found, they are associ-
ated with a lithology which indicates practically identical
conditions of deposition. On the other hand, and as a corol-
lary to this fact, they show no evidence of adaptation. These
species appear with unusual suddenness and abundance to-
ward the top of the Tipper Cretaceous, spread rapidly and
to great distances, and die out before the dawn of the Ter-
tiary as abruptly as they appeared. Throughout this com-
paratively short period geologically they apparently main-
tain a rigidly uncompromising individuality. However, the
fact that the fossil form called Belemnitella is merely a small
internal vestige of a once-enveloping shell, and hence far
108 Belemnitella Americana and Mucronata [306
from a trustworthy guide to the adaptable characteristics of
the form, vitiates to a certain extent any general conclusions,
such as that wide-spread occurrences of type fossils indicate
correspondingly widespread similarity of life conditions.
Nevertheless, the apparent inability of these Belemnitellas to
live except in a certain, rather fixed environment, is at least
suggestive that their powers of adaptation were limited.
Whitfield (1) describing the American species writes as
follows :
" Stylet or guard, rather large, solid, and heavy, often becoming
thickened with age. Specimens varying from nearly 3 inches to
nearly 4 inches in length below the base of the slit, the larger ones
evidently having a length of fully 6 inches, from the lower extremity
to the top of the internal cavity, or conotheca. General form triangu-
larly cylindrical in the upper part, becoming flattened on the ventral
side in the lower part, with frequently a slight mucronate extremity.
. . . The upper end of the stylet or guard, from about the base of the
internal cavity, gradually expands upward, and becomes very thin on
the edge, and the inner surface of the wall often bears the marks of
the transverse septa of the phragmacone. The entire surface is
usually much roughened When not worn, the roughening being great-
est on the ventral side, while laterally this roughening produces vas-
cular lines running obliquely backward, in crossing from the ventral
to the dorsal surfaces, and on the raised lanceolate, area of the
dorsal surface the markings are finer and arranged so as to produce
longitudinal lines, or interrupted striae."
There seems to be a fair degree of unanimity as to the
similarity of B. americana (Morton) and the European form,
B. mucronata, D'Orbigny. Morton says (2, p. 190).
" This species has an analogue in the B. mucronata of Schlotheim,
which is characteristic of the Chalk throughout Europe. It seems
also to resemble the belemnite of Maestricht, as figured by Faujas."
D'Orbigny, (3, p. 63-4) describes the European form as
follows:
"Rostre" allonge", quelquefois un peu comprime", cylindrique sur sa
moitie" ante"rieure, de 1& acumine" jusqu'a 1'extremite" tres -obtuse, au
milieu de laquelle est une pointe souvent assez allonge"e; les deux
impressions dorsales sont tres marquees, large, et il en part des
petits sillons ramifies et reticule's, qui viennent joindre le partie in-
307] G. E. Dorsey 109
Scissure long, occupant la moitie de la cavite". Cavite"
ronde, tres-longue, conique, occupant les deux cinquiemes de la lon-
guer, pourvues en dessus d'un sillon creux longitudinal; alveole avec
des cloisons separges, dont les traces se montrent encore dans la
cavite. Jeune, sa form est plus conique et le"gerement comprime'e."
Despite the fact that B. americana and B. mucronata are
regarded as type fossils, and that the two forms are regarded
as closely related, they do not represent exactly the sam^
horizons on both sides of the Atlantic, the American form
being somewhat older than its European analogue.
One of the typical American occurrences is in the Mon-
mouth formation of the Upper Cretaceous of New Jersey.
J. A. Gardner (4, p. 396) says,
"It (B. americana) is perhaps the most valuable horizon marker
of the Cretaceous, since it has never been reported from either above
or below the Monmouth, and is determinable from the merest frag-
ment."
The Monmouth formation, whose type locality is in Mon-
mouth County, New Jersey, has been divided by W. B. Clark,
in ascending order, into the Mt. Laurel sands, the Navesink
marls, and the Redbank sands. The Belemnitella zone in
New Jersey occurs at the Navesink marl level and thus is
about midway in the Monmouth. To the south, B. americana
is found in the Peedee formation of North and South Caro-
lina, and farther to the south in the Exogyra costata zone
of the Selma Chalk.
It apparently dies out before the deposition of the upper
Monmouth. In Europe, B. mucronata is first found in the
late Campanian. It continues throughout the Maestrichtian,
that is throughout the Aturian or uppermost Senonian. The
overlying Danian from which it is absent is correlated with the
New Jersey Rancocas and Manasquan formations. Thus, if,
as Clark says (4, p. 74), "The (Monmouth) forms point
to the lower Senonian age of the beds," then the presence of
B. mucronata in the Maestrichtian is decidedly younger,
particularly so since Belemnitella is not present in America
even in late Monmouth time.
110 Belemnitella Americana and Mucronata [308 •
The striking fact about both the American and European
occurrences is that B. americana and B. mucronata are prac-
tically always found in "greensand," of a very glauconitic
nature, or in chalk. The explanation of this rather unex-
pected uniformity will be discussed after a brief review of
the occurrences on the two continents.
The marine Upper Cretaceous of North America is not
found farther north along the Atlantic coast than Long Is-
land where, however, only the earlier horizons are repre-
sented. M. L. Fuller (5, p. 77) says that well-borings are
sufficiently numerous to make it perfectly clear that there
are, on Long Island, no thick greensand beds like those in
New Jersey, their stratigraphic position being occupied by
sands. A reference to his list of Cretaceous fossils (p. 78),
reveals the entire absence of B. americana from all of these
beds.
As noted above, the Navesink marls of New Jersey are the
most northern occurrence of B. americana. This member,
representing the middle Monmouth formations of New Jer-
sey and Maryland, embraces the Lower Marl Bed of Cook,
concerning which, W. B. Clark writes (6, p. 191): "The
lower Marl Bed is a characteristic greensand, glauconite en-
tering to a marked extent into its composition." The same
author (7, p. 334) writes of this formation, "The Navesink
marls are typically glauconitic sands. . . . The basal por-
tion consists generally of arenaceous beds that have been
hitherto referred to under the name of sand marl. Above
the sand marl in the northern portion of the area, is a very
compact blue marl, which is highly glauconitic, and fre-
quently fossiliferous in its central portions."
The Monmouth formation reappears in Delaware and Mary-
land, where it has lost the three-fold characteristic of the
New Jersey section. As the beds appear in northeastern
Maryland and Delaware they still preserve their remarkably
glauconitic character. Clark (4, p. 70) says, "The Mon-
mouth formation consists chiefly of reddish and pinkish sands,
generally glauconitic, the beds in places forming a dark
309] G. E. Dorsey 111
greensand." This is true to a marked extent for only the
beds along Bohemia Creek in Maryland, in the northeastern
part of the state. The Monmouth, as it occurs on the West-
ern shore of the state, from Anne Arundel to Prince George's
county, has lost the markedly glauconitic character of the
Bohemia Creek facies, — clays and muds being considerably
more prominent. It is especially significant, in view of the
above, that we find B. americana in abundance on the Eastern
shore in the glauconite, and no trace of it on the Western
shore in the muds and clays.
Weller (22, p. 18) has called attention to the fact that the
Eedbank sands of New Jersey pinch out passing to the south-
west, their stratigraphic position being occupied by the Nave-
sink marls which here still maintain their glauconitic facies.
Accordingly, as one progresses toward Delaware and Mary-
land from Long Island, he passes through a series that is
progressively more glauconitic, until over southwestern New
Jersey, Delaware, and northeastern Maryland is located the
greatest development of this facies. Still farther toward the
southwest, the greensand aspect gives way to muds and clays,
until one reaches the Virginia land mass. This points pretty
definitely to the existence of a basin in which glauconite was
being deposited, far enough removed from land, or with such
a slight influx of terrigenous materials, as to give clear, quiet
waters, during a large part of Monmouth time.
As noted above, Virginia was above water during the Mon-
mouth, but in North Carolina, in the so-called Peedee sands
of Ruffin, we have conditions of sedimentation almost iden-
tical with those of the New Jersey-Delaware-Maryland Mon-
mouth,— a series of alternating sands and clays, the sands
being highly glauconitic. According to Stephenson (8, p.
146), "The content of glauconite in the greensands of North
Carolina appears to be less than that of the greensand marls
of New Jersey." A careful study of the sections of those
localities at which B. americana is found, reveals, without
exception the highly glauconitic nature of the fossil-bearing
112 Belemnitella Americana and Mucronata, [310
beds. A few examples may be selected at random, B. ameri-
cana being recorded from each locality (8) :
U. S. GEOLOGICAL SURVEY, LOCATION 4133 (p. 153)
Pleistocene
Loose, light sand 6 ft.
Unconformity
Cretaceous (Peedee sand)
Firmly indurated, dark gray, calcareous, glauconitic
sand, containing many fossils 2 ft.
Dark green, argillaceous, micaceous, rather coarse
sand, containing a few fossils 7 ft.
U. S. G. S. LOCATION 4130 (p. 154)
Pleistocene
Loose white sand 8 ft.
Unconformity
Cretaceous (Peedee sand)
Dark green, glauconitic sand 1 ft.
Greenish gray, glauconitic and calcareous sandstone,
containing numerous fossils l%ft.
Dark greenish gray glauconitic sand, containing a
few fossils 2 ft.
U. S. G. S. LOCATIONS Nos. 4169 AND 4137 (p. 157)
Pleistocene
Sand and loam poorly exposed 15 ft.
Eocene
Thin-bedded shale with conglomerate band at base . . 7 ft.
Unconformity
Cretaceous (Peedee sand)
Dark green, very compact, arenaceous, glauconitic,
micaceous clay, containing numerous shells and
casts 11 ft.
Concealed, to waters edge 3 ft.
The report states that from this locality the B. americana were
collected from the greensand.
This series of sections, illustrating the association of green-
sand with the Belemnitella remains, could be continued until
every locality was listed. There are localities given, where, in
the Peedee greensands, no remains of Belemnitella have been
recovered. But this can not be regarded as evidence of any
kind. The fact that B. americana lived only under conditions
311] G. E. Dorsey 113
where glauconitic deposition could take place, does not neces-
sarily imply that it lived everywhere where such conditions
existed, any more than its isolated occurrence in beds of
neither a glauconitic nor a chalky phase proves that the con-
stant association with such phases is 'of no significance. The
close proximity of the localities in the Carolinas, however, and
the evidence in favor of fairly widespread similar conditions
during Peedee time point rather to incomplete fossil col-
lections than to absence of the form. '
Passing to the south, and southwest, the horizon of the
Monmouth, marked by greensands thus far, gives way to
chalk. The Selma Chalk, the time equivalent of part of the
Eipley, is the next source of B. americana. The greatest
development of the Selma Chalk is in central and western
Alabama, and in east-central Mississippi. To the north in
Mississippi the Chalk thins rapidly and becomes very argil-
laceous, and in Tennessee is a very thin basal layer of the
Eipley formation. An examination of the tables of species
prepared by L. W. Stephenson (9, facing p. 24) reveals the
widespread occurrence of B. americana in the Selma Chalk.
Thus in east central Mississippi and adjacent parts of Ala-
bama, it is recorded from 9 localities; in the region of War-
rior and Tombigbee rivers, Alabama, from 2 localities; from
the vicinity of the Alabama Eiver, Alabama, from 2 locali-
ties. About a quarter of a mile east of Troy, Mississippi, an
occurrence of B. americana is recorded at about the juncture
of the Selma and the Eipley (U. S. G. S. Location 6471) ;
and in the northern Mississippi area (N. B. % Sec. 14, T.
4 S., E. 5 E., at U. S. G. S. Location 544) the form has been
recorded in the Eipley formation ; and there is no record of its
occurrence in the Selma Chalk proper in either of these imme-
diate regions. Inasmuch as B. americana occurs over this
large area, practically everywhere in the Selma Chalk, which
" consists in the main of more or less argillaceous and sandy
limestones, rendered chalky by their large content of Fora-
miniferal remains, with interbedded layers of nearly pure,
Belemnitella Americana and Mucronata [312
hard limestones at wide intervals," and as chalk has been
found to be one of the two facies in which B. americana prac-
tically always occurs, the various localities need not be consid-
ered in detail. In the case of the two Eipley occurrences,
however, the lithology must be examined.
Dr. L. W. Stephenson, of the U. S. Geological Survey, has
kindly furnished me with the following information in regard
to these occurrences. The locality one-quarter mile east of
Troy, Mississippi, came from a "gray, highly calcareous
sandstone," of which Dr. Stephenson sent me a sample. The
rock bears not the slightest trace of glauconitic material, but
is composed to a very large degree of limestone, of a chalky
character. In places the sand grains, — milky quartz, — are
embedded in a solid calcareous matrix. Thus, while not per-
haps occurring in the Selma Chalk proper, the lithology of
the beds may be regarded as identical with that of many
parts of the Chalk formation. Of location 544, in Tippah
County, Mississippi, Dr. Stephenson says, " the matrix at-
tached to one specimen in the lot is gray, calcareous, glau-
conitic ( ?) sand." This specimen is a Serpula. He does not
go into further detail regarding the locality, but it may be
a fair inference, despite a warning that some of this material
may be mixed, that glauconite was present at least in the
vicinity of this occurrence of B. americana. It is rather
significant in this connection to note that the glauconite
locality was in the true Ripley, at some distance from the
Selma Chalk, and the non-glauconitic, but highly calcareous
facies, was very near to the contact of the Selma and Ripley.
The most noteworthy gap in the range of B. americana in
the southeastern United States is in Georgia. Here the
Eipley formation is well developed, attaining a maximum
thickness of about 850 feet, but nowhere in the large area
covered by the formation, which at times is somewhat glau-
conitic, is B. americana recorded. The many sections of the
Ripley given by Veatch and Stephenson (10), and the nu-
merous fossil collections, never mention B. americana. This
is probably due to the Georgian Ripley being a nearer-shore
313] G. E. Dorsey 115
deposit than the Selma or the Eipley to the west. Through-
out the Ripley in Georgia are found remains of plants and
lignite, clearly pointing to an estuarine or very near-shore
origin. On the other hand, Professor E. W. Berry has in-
formed me that to his knowledge there has never been a
piece of lignite found in the Chalk. The grading of the
Chalk, to the east, into sands and muds, is thus to be taken
as indicating an approach to land, and hence to compara-
tively muddy waters, which we shall see were intolerable sur-
roundings for this species.
This list of occurrences exhausts the localities for B. ameri-
cana. It is restricted to the Atlantic and Eastern Gulf pro-
vinces of the United States, — occurring at the Monmouth or
Exogyra costata level of the Upper Cretaceous along the At-
lantic coast and in the eastern part of the Mississippi Embay-
ment. The generalization that B. americana occurs mainly in
a chalky or a glauconitic-greensand facies will be seen to hold
true to a remarkable extent throughout this range. Although
absent in many instances in favorable lithology, I have yet
to discover an occurrence in a facies radically different from
the above.
The European occurrences of the form, known as Belemni-
tella mucronata, D'Orbigny, conform in every way to the re-
strictions in lithologic characteristics imposed by B. ameri-
cana. As noted elsewhere, the European horizons at which
B. mucronata occurs are slightly younger than the American.
We first observe its presence in the uppermost Campanian,
but it is the Maestrichtian that witnesses its widespread dis-
tribution. A glance at a map (e. g., Haug, 13, p. 1299)
showing the distribution of the various Neocretaceous de-
posits will show that the occurrence of chalk is, broadly, in
a northwest-southeast belt, from Antrim in Ireland, across
England, into Germany and Poland, and along the eastern
front of the Carpathian Mountains, with large areas in cen-
tral and eastern Eussia, and the Caucasus and Trans-Cau-
casus. Southwest from this main basin, from Sweden through
eastern France, is a subordinate trough, with a few isolated
116 Belemnitella Americana and Mucronata [314
localities in west France, in Charente, these two basins form-
ing the legs of a triangle; and finally, eastward from the
southern limit of this trough, across the present site of the
Alps, connecting the two legs of the triangle is a subordinate
basin, in which marls and limestones were deposited, connect-
ing with the basin of Eussia.
This rough triangle around Germany left the greater part
of the German Empire above water during late Senonian
time. A. E. Wallace (15, p. 91) quotes Sir Charles Lyell as
follows, "pure chalk, of nearly uniform aspect and compo-
sition is met with in a northwest and southeast direction,
from the north of Ireland to the Crimea, a distance of about
1140 geographical miles; and in an opposite direction it
extends from the south of Sweden to the south of Bordeaux,
a distance of about 840 geographical miles." Wallace goes
on to say that, while this marks the extreme limits within
which true chalk is found, "the chalk is by no means con-
tinuous. It probably implies, however, the existence across
central Europe of a sea somewhat larger than the Mediter-
ranean."
The most widespread and the most typical chalks of Upper
Cretaceous age are those represented by the Upper Chalk of
England, and its equivalents, the Campanian and Maestricht-
ian, of the continent. In northeastern Ireland, in Antrim,
under a Tertiary basaltic flow, resting uncomformably on
Liassic and Ehaetic strata, Jukes-Brown (11, p. 322) gives
the following series, all of Upper Chalk age: —
3. White limestone, with B. mucronata 100 ft.
2. Hard, pinkish, glauconitic limestone, with quartz
grains, and phosphatic nodules 4 ft
1. Glauconitic limestone, passing down into glauconitic
sand 16 ft.
Geikie (12, p. 1194) refers to this series as "Hard white
chalk, 65 to 200 feet, with Echinocorys [Ananchytes] sul-
catus, etc. = Zone of B. mucronata." Very little referable
to the Upper Chalk remains in Scotland, but in the west,
under the volcanic plateaus of Mull and Morven, some of the
315] G. E. Dorsey 117
Upper Chalk is found. Jukes-Brown (11, p. 322) says re-
garding this, "The white sandstones of the west coast are
overlain by a few feet of argillaceous greensand, passing up
into glauconitic limestone, the two being only five to seven
feet thick. . . . Above these is a bed of white B. mucronata
chalk, from three to ten feet thick, which is evidently a mere
remnant of a much thicker deposit."
In England, the Belemnitella zone of the Upper Chalk has
been traced from Kent to Dorset, along the Channel, and
thence northeastward to Norfolk. It reaches a thickness of
100-160 feet in the Hampshire basin, and in Norfolk it
attains its maximum development. Near Norwich, Geikie
(12, p. 1193) describes it as a "white, crumbling chalk, with
layers of black flints, which have yielded abundant sponge
spicules." Everywhere in the British Isles where B. mu-
cronata has been found, it has been in a pronouncedly chalky
matrix.
On the continent, around the eastern shores of the Baltic,
the Senonian is present as white cliffs, in Pomerania, in
Riigen, along the south shores of Sweden, and the Danish
islands. It is also present in Liinberg in east Prussia. While
some B. mucronata are recorded in the Campanian (Haug,
13, p. 1301), it is first mentioned in this region in the upper
Maestrichtian, in a lithology of persistent white chalk. Haug
remarks in connection with this occurrence that as in the
Paris Basin, the ammonites are rare, and one is certainly
in the presence of deposits of shallower seas than those over
Hannover and Westphalia. Ananchytes ovatus, Magas pu-
milis,, and Terebratula earned are abundantly associated with
the Belemnitellas.
Passing to the vicinity of the Anglo-Parisian Basin, we
find in the neighborhood of Lille, and in the province of
Hainaut in Belgium, the Campanian very slightly fossil-
iferous, but the Maestrichtian well represented by six zones,
according to Haug (13, p. 1302-3), in every one of which
B. mucronata is recorded. The lithology varies from a phos-
phatic conglomerate at the base, with broken remains of B.
118 Belemnitella Americana and Mucronata [316
mucronata, through chalks of varying degrees of purity, with
an occasional conglomerate intercalated, to the basal con-
glomerate of the "tuffeau de Ciply," which transgresses the
two upper zones of the Maestrichtian proper. In the pro-
vince of Limburg, in Belgium, the Campanian, though glau-
conitic, has not as yet yielded any Belemnitellas ; but the
Maestrichtian, here divided into five zones, contains B. mu-
cronata throughout. It is worth while looking at the lithol-
ogy of each of these for a moment (13, p. 1303-4) : —
Zone 1 — (oldest) Glauconitic chalk with B. mucronata.
Zone 2 — Pure white or marly gray chalk, without flints, with B.
mucronata.
Zone 3 — Thick white chalk with black flints, with B. mucronata,
grading off laterally into the Kunraed limestone, —
marly, gray, very fossiliferous, but no B. mucronata.
Zone 4 — Tuffs, with gray flints, with B. mucronata.
Zone 5 — Tuffs, with numerous gastropods, and a few cephalopods,
among these being B. mucronata.
Haug, referring to this succession (p. 1304), says the
Maestrichtian of Limburg is essentially a neritic formation,
offering few or no paleontologic affinities with the bathyal
type of the stage, such as existed in the northeast of Germany.
In the Paris Basin, proper, the Upper Senonian is divided
according to Grossouvre, into the following :
Campanian
Zone 1 — Gray chalk of Hardivillers.
Zone 2 — Upper Chalk of Reims, White Chalk of Hardivillers,
and Chalk of Michery, with B. mucronata.
Maestrichtian (craie de B. mucronata) Chalk of Meudon, of Mon-
terau, and of St. Aignan, with B. mucronata.
The fauna of the chalk of Meudon is very rich, but ammon-
ites are rare in it, while Inoceramus, Pecten, Ostrea, and
Brachipoda are well represented. In the southern part of
the Paris Basin the Maestrichtian is represented by only its
lower beds, the time of the typical Maestrichtian of the
northeast being a period of emergence in this region. In
Normandy, however, the Maestrichtian is the only member
317] G. E. Dorsey 119
of the Senonian present. Here it is a sandy, chalky deposit,
and contains great numbers of fossils, B. mucronata among
them. This occurrence is very similar to the Maestrichtian
of the Baltic provinces and Belgium.
In the Aquitanian region, conditions similar to those in
Touraine prevailed, except that here the Campanian in Cha-
rente does not carry B. mucronata at all, and the Maestricht-
ian, divisible into three zones, is present in its entirety. But
only in the lowest zone — a white limestone, with bryozoa,
oysters, etc., — is B. mucronata found. The upper two, con-
sisting of ferruginous sands and yellow limestones are proba-
bly too littoral in character to contain B. mucronata. Haug
calls the Charentian- Senonian neritic. In the south, in the
vicinity of Lyons, the Senonian, — here apparently undifferen-
tiated — rests upon the Albian, and contains B. mucronata
and Ananchytes ovatus. The matrix is a grayish white lime-
stone. Similarly, in the Alps, at Geneva, in a marly, gray
limestone, with siliceous beds of Foraminifera in the upper
part, the undifferentiated Senonian rests upon the Albian,
and contains B. mucronata, with Ananchytes ovatus, and
some Inocerami. Both of these occurrences are questionably
referred to the Maestrichtian.
From the region of Lake Geneva, the Senonian deposits
occur in a narrow strip across the Alps, being especially well
studied in the northern and eastern Alpine regions. At
Tolz, in Bavaria, there is a greensand, containing sponges,
gastropods, and B. mucronata. Between Bergen and Teisen-
dorf, in the same region, are forms like the neritic species of
the Maestrichtian of Limburg, in a great thickness of marls
containing B. mucronata near the top. North of Salzburg,
in western Austria-Hungary, the Senonian, composed largely
of marls, contains B. mucronata.
The " couches de Gosau," a name applied to a series of
conglomeratic and marly beds south of Salzburg, in the pro-
vince of Salzburg, is divided into five zones, the uppermost
of which, the marly "couches de Merenthal," contain B.
mucronata and are correlated with the Maestrichtian. In
120 Belemnitella Americana, and Mucronata [318
the southern Alps, B. mucronata occurs in a thick series of
marly limestones, with a fauna composed of pelycypods and
cephalopods, known as "Petage de Brenno."
In the East Russia-Poland-Carpathian region, the chalk
covers vast areas, and everywhere has the same facies as that
of the Anglo-Parisian Basin and north Germany. Over
Poland and East Eussia the greater part of the fossils come
from the Maestrichtian, which is a typical chalk. To the
south, although the Maestrichtian is present over large areas,
its facies has so changed (to sands and clays) that B. mu-
cronata is rarely present. When, however, we do find it, the
accompanying lithology is unchanged. In the Bulgarian pla-
teau and the Dobrudja, there is a thick series of Senonian
age, whose upper part is composed of white, porous lime-
stones, with siliceous lenses,: — in every way, Haug says, like
the Anglo-Parisian Maestrichtian, and here we find B. mu-
cronata. In the Crimea, the Campanian and lower Maes-
trichtian are composed of white chalk, in which B. mucronata
is present. The Senonian of the Caucasus is usually a white
chalk, very similar to that of the Anglo-Parisian basin, and
with B. mucronata. Near Toupiniza, in Servia, an occur-
rence of B. mucronata is mentioned in marly sands, but this
is very near the region of the Dinaric Alps, where the chalky
limestone facies, which is characteristic of the Maestricht-
ian in most of eastern Europe, is absent. The geology of
Croatia, Dalmatia, and Bosnia is in such an unknown con-
dition, that exactly what is present can not be said, but no
record of B. mucronata was found.
Passing from the Balkans, the next, and last, occurrence
of B. mucronata is in the Magishlak peninsula, on the north-
east coast of the Caspian Sea. Here the following beds are
differentiated (13, p. 1337) :—
Zone 1 — A white chalk, with Ananchytes ovatus, Inoceramus bal-
ticus, Pycnodonta vesicularis, Belemnitella mucro-
nata.
Zone 2 — A marly and glauconitic chalk, with Ananchytes ovatus,
Magas pumilis, Pycnodonta vesicularis, Scaphites
schluteri, Hamites roemeri, B. mucronata.
319] G. E. Dorsey
Zone 3 — Some limestone, with Echinoconus conicus, Ananchytes
ovatus, Scaphites constrictus, Baculites incurvatus.
Zone 4 — Some marly sands, with Ananchytes sulcatus, Terelra-
tula fallax, and faxoensis, Pycnodonta vesicularis.
The above is a good example of what is contairmally being
repeated in the recorded occurrences of this Belemnitella
form. Where there is a chalky or a glauconitic facies the
form is present. When this changes to anything else, it is
almost invariably absent.
The most prominent exception to this, as will be seen from
the facies given above, is the area across the Alps, — the basin
connecting the two main basins from England to Kussia and
from Sweden to France. Here B. mucronata occurs most
often in a marly or marly limestone facies. It is likely that
most of the surrounding country in the late Senonian was
peneplained, which would permit clear water in very near
shore deposits, and explain the occurrence of limestone with
marls. If B. mucronata, ranging far and wide over areas in
which chalk was being deposited were to stray into this basin,
open to the two regions of congenial habitat, they might either
pass through to the far basin, or die on the way. If such a
condition had existed we should expect to find the form
exactly as we do find it, erratically distributed in changing
lithology.
If we pursue our search for B. mucronata farther to the
east, into Persia, Turkestan, Siberia, China, Japan, Alaska,
we everywhere find it absent. Although the Senonian is
present in much of this area, there are no occurrences of B.
mucronata recorded.
The Senonian, as it occurs around the western shores of the
Mediterranean Sea, will afford a rather impressive illustration
of the way in which, with a change in the facies of the beds, B.
mucronata vanishes. In Sicily, and in Spain, the Senonian
is present as sands with occasional limy lenses. In Italy the
Hippurites limestone is well developed. In Tunis the late
Cretceous is represented by white limestones, alternating with
yellow marls. In the south of Tunis there is also a very well
122 Belemnitella Americana and Mucronata [320
known fauna, from a great thickness of Senonian, in which all
stages have been differentiated. In Morocco there is less
known about the Senonian, but in all of these occurrences
B. mucronata is noticeable only by its absence. In Egypt the
Campanian and Maestrichtian are very well developed, the
latter becoming thicker as it passes southward. In the north,
it contains oysters and Exogyra overwegi; to the south, where
the facies is one of ferruginous sands, and gypseous and salt-
bearing clays, attaining a thickness of 150 meters, Zittel has
recorded a very large fauna, with no B. mucronata.
Such negative evidence could be continued indefinitely,
always affording striking corroboration of the evidence af-
forded by its occurrence. I do not see how it is possible to
escape the conclusion that there is undoubtedly some connec-
tion between the conditions under which glauconite and
chalk were deposited, and endurable life conditions for B.
mucronata and B. americana. Also, the abruptness with
which they disappear when any other facies occurs seems
to indicate a very restricted power of adaptation. Does their
occurrence in glauconitic sands and chalk indicate the maxi-
mum effort of this limited power of adaptation under two dif
ferent conditions of life, or do the glauconite and chalk mean
practically identical conditions of deposition? The latter, in
the light of the most recent interpretation of these facies, is
to be regarded as the correct conclusion.
The bathymetric conditions under which chalk was laid
down have been the source of much speculation, which has
gradually undergone a most marked change. The venerable
and orthodox idea is that the chalk is a deposit formed in a
large ocean at great depths, — that it is an abyssal deposit com-
parable to the Globigerina-ooze of recent seas. The large pro-
portion of Foraminifera was regarded as proof of this. Cayeux
(14, p. 523-4) give a resume of the various expressions of
opinion on the origin of chalk, dating from 1833 to the end of
the nineteenth century. Mantell, in 1833, and E. A. C.
Austin in 1843, both postulate abyssal conditions. Good-
win-Austin in 1858 writes that A. D'Orbigny and E. Forbes
321] G. E. Dorsey 123
believe in the deep-sea origin of chalk, and he adds that
the organic remains in the chalk were carried there by cur-
rents from regions of shallower water. In 1863 Hebert
said the chalk of the Paris Basin was formed at a suf-
ficiently shallow depth for it to take part in .a period of
emergence, being the first hint that chalk might not be
abyssal. Delesse was the first to introduce warmth as one of
the requisites for chalk deposition, when he said, in 1866,
that the water of the Paris Basin was of the same tempera-
ture as that of the Gulf Stream today. Then followed in
order, W. Thompson, Prestwich, Whitaker, M. J. Murray, all
subscribing to the deep-sea origin. In 1877 the first dis-
cordant note was sounded by Gwyn-Jeffreys, who declared the
molluscs of the chalk were shallow water and tropical forms.
A. Geikie, in 1879, supported this idea. Sollas says the
sponges indicate a depth of 100-400 fathoms. Lambert, and
Prestwich in a later article, Peron, Neumayr, Agassiz, and
Jukes-Brown have all held that the chalk was formed in deep
waters. But the many indications of emergence that have
been found associated with the chalk throughout Europe, and
the absence in the main of any organisms that can only be
abyssal, have caused most present-day geologists to abandon
this idea. A. R. Wallace (15, p. 87, et seq.), in 1880, dis-
cusses the origin of chalk as follows:
" There seems very good reason to believe that few, if any, of the
rocks known to the geologists correspond exactly to the deposits now
forming at the bottom of our great oceans. The white oceanic mud,
or Grlobigerina-ooze, found in all of the great oceans at depths vary-
ing from 250 to nearly 3,000 fathoms, and almost constantly in
depths under 2,000 fathoms, has, however, been supposed to be an
exception, and to correspond exactly to our white and gray chalk.
This view has been adopted chiefly on account of the similarity of
the minute organisms found to compose a considerable portion of
both deposits, more especially the pelagic Foraminifera, of which
several species of Globigerina appear to be identical in the chalk and
the modern Atlantic mud. . . . Now as some explanation of the
origin of chalk had long been desired by geologists, it is not sur-
prising that the amount of resemblance shown to exist between it
and some kinds of oceanic mud should at once have been seized upon,
124 Belemnitella Americana and Mucronata [322
and the conclusion arrived at that chalk is a deep-sea oceanic forma-
tion exactly analogous to that which has been shown to cover large
areas of the Atlantic, Pacific, and Southern oceans.
" But there are several objections to this view which seem fatal to
its acceptance. In the first place, no specimens of Globigerina-ooze
from the deep ocean-bed yet examined agree even approximately with
chalk in chemical composition, only containing from 44 per cent, to
79 per cent, of carbonate of lime, with from 5 per cent, to 11 per cent,
of silica, and from 8 per cent, to 33 per cent, of alumina and oxide
of iron. Chalk on the other hand contains usually from 94 per <;ent.
to 99 per cent, of carbonate of lime, and a very minute quantity of
alumina and silica. . . . Sir Charles Lyell well remarks that the
pure calcareous mud produced by the decomposition of the shelly
coverings of mollusca and zoophytes would be much lighter than
argillaceous or arenaceous mud, and being thus transported to
greater distances, would be completely separated from all impurities
. . . Mr. J. Murray . . . says . . . ' The Globigerina-oozes which we
get in shallow water resemble the chalk much more than those in
deeper water.' Mr. GUvyn- Jeffries, one of our greatest authorities on
shells, taking the whole series of genera which are found in the chalk
formations, seventy-one in number, declares that they are all com-
paratively shallow-water forms, many living at depths not exceeding
40-50 fathoms, while some are confined to still shallower waters."
Wallace discusses the occurrences of the chalk in the two
great areas, from Antrim to Crimea, and from Sweden to
Bordeaux, and says it is absurd to suppose that these areas
were oceanic abysses, since we have good evidence for believ-
ing there was land in Germany and in several of the nearby
regions. Moreover, the frequent intercalations of sandstones
and conglomerates, limestones, marls, and muds, contain-
ing many of the same fossils as the chalk do not add to the
abyssal theory. Finally, he says, the wide-spread emergence
at the end of the Mesozoic, evidenced by unconformities which
point to a Europe very similar in outline to that of today,
would make it extremely unlikely that there had been any
depths over Europe comparable to the present-day oceanic
abysses. Wallace of course makes no mention of the modern
theories of isostatic equilibrium which support his theory
admirably by the doctrine of the permanency of oceanic basins.
He reaches the conclusion that the chalk was a deposit laid
323] G. E. Dorsey 125
down under a depth of water varying from a few feet to 200
fathoms, and does not mean deep-sea conditions.
An argument favoring the warm-water origin of the chalk
is the result of the work of GL H. Drew., of the Carnegie
Institution, upon the precipitation of calcium carbonate from
the sea-water by bacterial agencies. He says (23, p. 136),
" Denitrifying bacteria possess the power of precipitating
soluble calcium salts in the form of calcium carbonate from
sea-water .... bacterial action may have formed an im-
portant part in the formation of the chalk and other lime-
stones rocks in geologic times." These bacilli, called " Bac-
terium calcis " by Drew, grew best on or near the surface in
water from 25 to 31.5 degrees C., with an average of 29 de-
grees; they will grow very slowly at 15 degrees C.; "but its
growth is totally inhibited at 10 degrees C." As such tem-
perature can only be attained in tropical and sub-tropical
oceans today, it is certain that the seas of the chalk must have
been of at least this warmth, if any of the chalk is due to
bacterial precipitation, — a view now very widely held.
Cayeux (16, p. 258-9), says, referring to the chalk of the
Paris Basin, " La craie du Nord est bien un depot terrigene."
A. Geikie agrees that it is a shallow water deposit. De Lap-
parent still inclines to the belief that it is a fairly deep-sea
accumulation. Schuchert (17, p. 885), says the evidence that
chalk is a shallow water deposit is, (1) the kinds of fossils
indicate shallow water, (2) the formations are accompanied
by sands, (3) in closely adjoining areas equivalent strata
contain no chalk. He sums the question up as follows: "It
is now held that the chalks are organic accumulations made
in the main by the calcareous skeletons of minute pelagic or
bottom-living plants and animals, in clear-water epeiric or
shelf seas, adjacent to low lands with mild climates/5
The most important feature of this summary is the clear-
water condition postulated. Recent work on the Selma Chalk
has shown it to be a deposit laid down in water into which no
muds or large amounts of sand were carried. The calcium car-
bonate, freed of all other sediments, accumulated in a com-
126 Belemnitella Americana and Mucronata [324
paratively shallow basin, very often not more than 25 fathoms
in depth. So with the great European chalk deposits. Their
purity is due rather to clear, shallow- water conditions, — condi-
tions which a flat, peneplained adjoining land-mass would af-
ford,— than to the clearness of abyssal oceanic waters. The
depth, or the distance from shore at which these conditions
would prevail, would be a function of the height of the land,
strength and direction of currents, mouths of rivers, etc. This
would suggest about the limit of the continental shelf, under
conditions as they exist today, but in the Cretaceous it is prob-
able that these existed at much shallower depths, for the
reasons given.
In the case of the glauconitic facies of the American hori-
zons, considerably more difficulty is experienced in reaching
a definite idea as to the conditions of deposition, due to the
lack of knowledge on the formation of glauconite. There
has been no controversy comparable to that over the chalk.
The consensus of opinion seems to place the areas over which
deposition is going on today at about the edge of the con-
tinental shelf, or at slightly shallower depths. Goldman (4,
p. 176-82), has a discussion of the glauconite of the Monmouth
formation of Maryland, but does not state at what depth it
was formed, although he says it is found at 91 meters in the
North Atlantic today (4, p. 176). Sir John Murray says the
glauconite, which is usually found in shells of Foraminifera
when primary, -is always associated with terrigenous material.
The admirable work of L. Cayeux (14), discusses rather the
method of formation of the mineral glauconite than the physi-
cal conditions under which it was deposited.
F. W. Clarke (18, p. 135), summarizes these as follows: —
glauconite "is widely disseminated upon the sea-bottom, but
most abundantly in comparatively shallow waters, and near
the mud-line surrounding continental shores," that is, "just
beyond the limits of wave and current action, or in other
words where the fine muddy particles commence to make up
a considerable portion of the deposits." This is usually placed
at or about the edge of the continental shelf, or from 80 to 100
325] G. E. Dorsey 127
fathoms. Fine particles of mud are, of course, as good indi-
cations of clear water as chalk. There seems to be a general
unanimity that quiet water is a requisite in the deposition of
the glauconite. Goldman (4, p. 178), in speaking of the
chemical reactions supposed to take place in the formation
of glauconite says, "but whatever the process, the fact may
be accepted that in the presence of abundant organic matter
in fairly quiet waters, FeS2 is formed." De Lapparent (19,
p. 365), says it is deposited in "green muds which form in
depths from 200 to 1300 meters along abrupt coasts, where
no important rivers empty as is the case along the south coast
of Africa and the coast of Australia." Graoau (20), says the
glauconite is formed in shallow water, on the continental
shelf, and is usually found as replacements in the fine marine
muds. Chamberlin and Salisbury (21, p. 366-68, Vol. i),
remark that " Glauconite is, on the whole, most abundant
along the edges of the continental shelves, though it is by no
means universal in this position. It is not commonly found
in deep water, nor very near the shore, but approximately at
the mud line."
But where clear, quiet waters prevail for any time, glau-
conite can be deposited, even if the waters are very shallow.
Thoulet has found it in the Gulf of Lyons from water of only
a few feet. Professor E. W. Berry informs me that he has
found glauconite in very near-shore deposits in the eastern
Gulf region of the United States. It seems probable, in view
of the predominance of sands, that the Cretaceous glauconite
was formed at shallower depths than that being formed today
near the edge of the continental shelf.
We are not concerned here with any of the discussions of
the chemical origin of glauconite. It may be formed after
the consolidation of rocks, as Cayeux has shown, and it may
not be due in any way to organic agencies. All we are in-
terested in is that the primary glauconite of the " greensands "
was deposited, in quiet waters, predominantly clear, sometimes
of very shallow depth, sometimes in depths of several hundred
feet.
128 Belemnitella Americana and Mwronata [326
It will readily be observed that such a conclusion is identi-
cal with that regarding the conditions under which the chalk
is thought to have been laid down, — warm,, clear, quiet waters,
from 50 to 2000 feet deep, the depth varying with the attitude
of the adjacent land masses, currents, etc. The glauconitic
and the chalky facies of the Upper Cretaceous may be taken,
with a considerable degree of certainty, to indicate practically
identical conditions of deposition, — conditions which, in view
of the comparative rarity of wide-spread similar deposits be-
fore and since, were produced by a rather exceptional combi-
nation of physical factors. In such surroundings B. americana
and B. mucronata appeared and rapidly became extremely nu-
merous. Everywhere in the Atlantic province they are found
flourishing while warm, quiet, clear waters prevailed. But
they rarely strayed far beyond the limits of these surround-
ings, and where they did they quickly died out. Finally, the
physical changes which brought the Monmouth and Maestrich-
tian to a close, in destroying the limited conditions under
which the forms could live, caused their complete extinction.
Nothing dogmatic can be postulated from the study of the
habitat of only one or two species. Before any universal con-
clusions can legitimately be drawn a very large number of
forms must be studied with extreme detail and exactness.
The forms I have used may be exceptional in their limita-
tions, and therefore possibly not typical examples of guide
fossils. But the evidence afforded by the occurrence of Be-
lemnitella americana and Belemnitella mucronata undoubtedly
points to the conclusion that the wide-spread occurrence of
identical forms, — which thus constitute intercontinental guide
fossils, — may be due to the wide-spread occurrence of identical
life conditions, rather than to an especially hardy, or easily
and rapidly adaptable form.
BIBLIOGRAPHY
( 1 ) R. P. WHITFIELD, " Gasteropoda and Cephalopoda of the Rari-
tan Clays and Greensand Marls of New Jersey." 1892.
U. S. Geological Survey, Monograph 18.
327] G. E. Dorsey 129
(2) S. G. MORTON, "Journal of the Academy of Natural Sciences
of Philadelphia." Vol. 6, 1829.
(3) A. D'OBBIGNY, " Pale^ontologie Francaise, — Terrain Cretace,"
Tome 1, Texte, 1840-41.
(4) Upper Cretaceous. Maryland Geological Survey. 1916, 2 vols.
(5) M. L. FULLEB, "The Geology of Long Island." 1914. U. S.
Geol. Survey. Prof. Paper 82.
(6) W. B. CLARK, "Annual Report of the State Geologist of New
Jersey." 1892.
(7) W. B. CLABK, " Bulletin of the Geological Society of America,"
Vol. 8, 1897.
(8) "The Coastal Plain of North Carolina." Vol. 3, Publications
of North Carolina Geologic and Economic Survey.
( 9 ) L. W. STEPHENSON, " Cretaceous Deposits of the Eastern Gulf
Eegion, and Species of Exogyra from the Eastern Gulf
Region and the Carolinas." 1914. U. S. Geol. Sur. Prof.
Paper 81.
(10) 0. VEATCH and L. W. STEPHENSON, "Preliminary Report on
the Geology of the Coastal Plain of Georgia." 1911. Bul-
letin 26, Georgia Geol. Sur.
(11) A. J. JUKES-BROWN, " The Building of the British Isles." 3d
Edition. 1911.
(12) ARCHIBALD GEIKIE, "Textbook of Geology." 4th edition, 1903.
2 vols.
(13) E. HAUG, " Traite1 de Geologic." 1908-11.
( 14 ) L. CAYEUX, " Contribution a l'6tude Micrographique de's Ter-
rains Se-dimentaires." Lille, 1897.
(15) A. R. WALLACE, " Island Life." 1880.
(16) L. CAYEUX, "Annales de la Societe Geologique du Nord."
Vol. 19. 1891.
(17) L. V. PIBRSON and C. SCHUCHEBT, "A Textbook of Geology."
2 vols. 1915.
(18) F. W. CLABKE, "Data of Geochemistry." 3d edition. 1916.
U. S. Geol. Sur. Bulletin 616.
(19) A. DELAPPABENT, "Traits de Geologic." 5th edition. 1906.
(20) A. W. GBABAU, "Principles of Stratigraphy." 1913.
(21) T. C. CHAMBEBLIN and R. D. SALISBUBY, "Geology." 1904.
3 Vols.
(22) STUABT WELLEB, "A Report on the Cretaceous Paleontology
of New Jersey." 1907.
( 23 ) G. HABOLD DBEW, " Report of Investigations on Marine Bac-
teria carried on at Andros Island, Bahamas, British West
Indies, May, 1912." Yearbook 10, Carnegie Institution of
Washington, 1912.
CONTRIBUTIONS TO
PLANT PHYSIOLOGY
CONTRIBUTIONS TO
PLANT PHYSIOLOGY
THE DEPARTMENT OF PLANT PHYSIOLOGY
By BURTON E. LIVINGSTON
The Department of Plant Physiology, established in the
autumn of 1909, has experienced a very satisfactory growth
during the seven and one-half years of its existence. It en-
tered the present Laboratory of Plant Physiology as soon as
the building was completed, in the winter of 1911-12. The
laboratory building has been described, with photographs and
plans, in the Johns Hopkins University Circular for Decem-
ber, 1916. The present paper is offered as a preface to the
following preliminary reports of plant physiological work
now in progress or recently completed, and deals with two
topics, the general aims of the department and the nature of
the work so far accomplished or in progress.
AIMS OF THE DEPARTMENT
Nature of the Science — Plant physiology occupies a some-
what uncommon position among the natural sciences, having
many of the characteristics of a young science, although it
is not really such. Notwithstanding the fact that people have
been interested in the physiology of plants for many genera-
tions, the subject has hardly yet become generally regarded
as a separate science, and it has usually been included under
the general designation of botany. Animal physiology, which
is, of course, the corresponding subdivision of zoology, has
long been considered as distinct. The simplest way to make
the content of plant physiology clear to one not acquainted
with it is to point out that it deals with plants in exactly the
same way as animal physiology deals with animals. Thus
it has to do with all the processes that go on in plants, and
it considers these processes just as physics and chemistry con-
331] 133
134 The Department of Plant Physiology [332
sider the processes that go on in inanimate things. Indeed,
the close relation between the physiology of animals and that
of plants is becoming so well appreciated in recent years that
a science of general physiology (dealing with the physics and
chemistry of all living things) appears to be rapidly devel-
oping. It is seldom possible to treat any physiological topic
adequately without reference to both plants and animals.
Some of the topics dealt with in plant physiology may be
mentioned as examples. Such are: water requirement; nu-
trition by inorganic materials; nutrition by organic ma-
terials; the exchange of energy between the organism and
its surroundings; the chlorophyll function; respiration, with
and without free oxygen; enzymes, activators, hormones, and
the general phenomena of catalysis; the control of growth
and development, including reproduction; the physiology of
movement and its control, and the physics and chemistry of
protoplasm.
The non-physiological aspects of biology may be grouped
together as morphology, which deals with the structures of
organisms. Perhaps one of the most noticeable aspects of
physiological endeavor, and one in which it differs remark-
ably from morphological study at the present time, is this,
that it has little to do with the general problem of evolu-
tion and phylogeny. Evolutionary philosophy has been
built up largely from morphological observations, and it is
only recently that it has become possible to relate different
organisms to each other with reference to their physical and
chemical processes. The evolution of animals and plants has
never yet been one of the main topics of physiology.
The sciences of mycology, bacteriology, pathology, ecology,
etc., all have their morphological and physiological aspects,
and their subject-matter may be treated from the stand-
point of static description or from that of process dynamics.
Thus, that branch of pathology which deals with the identi-
fication of parasitic organisms is mainly morphological in its
point of view, while the sciences of toxicology and immunology
are clearly branches of physiology. It is not without sig-
nificance that many of the characters by which the bacteria
333]
B. E. Livingston
135
136 The Department of Plant Physiology [334
are classified and identified are physiological, since the
processes induced by these minute organisms happen to be
more easily observed than are their structural differences.
Application of Physiological Science — Just as physics,
chemistry, climatology and biological morphology become
applied in physiology, so does physiology become applied in
many other lines of human activity. As with other sciences,
there are, in general, two groups of applications that are pos-
sible. First, there is the general application of physiologi-
cal knowledge and principle to the formation of what has
been called a "philosophy of the universe." This is perhaps
its application as "pure science/5 and for this application
plant physiology is almost, if not quite, as valuable as is
animal physiology. Such application is not usually called
an application at all, not being primarily practical for the
physical aspects of human life, in the sense of "buttering
bread." But there are still men who do not live by bread
alone, and a commercial age has not yet proved that a gen-
eral appreciation of the relations of the things about us may
not be ultimately as valuable to the human world as are
those things which money buys directly. It is in this direc-
tion of application that modern natural science claims at
least an equality with philology, history and the other
humanities.
The second group of applications possible for physiologi-
cal science includes those commonly called practical, by which
food and clothing and dwellings may become more readily
available to human beings, and by which human health and
comfort may be enhanced. Just as animal physiology finds its
most numerous applications of this sort in the fields of medi-
cine, surgery, hygiene, animal husbandry, etc., so plant physi-
ology contributes most to human physical welfare in the
fields of agriculture, forestry, fermentation operations, bac-
teriology, etc. These applications are more interesting to
more persons than are those of the first group and their
importance is not to be minimized. Indeed, the more a sci-
ence may be practically applicable the more opportunity it
may have for becoming philosophically applicable. The two
335] B. E. Livingston 137
kinds of application advance hand in hand, but the great
majority of individuals may remain generally careless of the
philosophical kind. For the growth of plant physiology and
for its best service to the world, it is clear that most of its
devotees must give much attention to the practical problems
of plant production and plant culture, and such is indeed
the case.
Both groups of applications have their philanthropic or
altruistic and their personal or selfish aspects, using these
adjectives in their usual sense. Thus, a world philosophy may
be cultivated with the conscious aim of advancing human de-
velopment in general, or with the aim of advancing certain
individuals, groups or institutions, as by increased financial
income. Of course, the two aspects overlap, but the broadly
philanthropic aim seems to have been frequently more evi-
dent than the other among the great philosophers and re-
ligionists of the past. We are not told that a Buddha or a
Christ or a Pasteur has given much attention to personal
financial income or to the copyrighting or patenting of his
ideas. Nevertheless, it is quite possible for a modern philo-
sophical scientist to give attention to such personal things
without detracting from the broader value of his work.
The practical applications of a science such as plant physi-
ology may be carried forward for either altruistic or personal
ends. The latter kind of activity is commonly called com-
mercial. A plant physiologist may work for years in per-
fecting methods for the production of better or more abund-
ant agricultural crops, and his main aim may be either to
lower the cost of food to the multitude, or to gain for him-
self fame or financial profit. The work itself may be the
same in both cases, and even the publication of his results and
conclusions may not be markedly different. However, as in
all such personal activities, the results eventually become free
to the world, and may thus become just as important in gen-
eral human advancement as though the work had been planned
with that end in view. Personal interest can usually withhold
results of this kind for only a limited time; patents and copy-
138 The Department of Plant Physiology [336
rights run their courses and commercial secrets are sooner or
later divulged. As has been remarked above, the two points
of view overlap, an individual's -motives are seldom or never
exclusively of the one or of the other kind, and they shift
from time to time.
It has seemed desirable to give space to the discussion just
presented, on account of the long-standing misapprehension
that still exists between the exponents of "pure science" and
those of the arts and commercial applications of science. The
writer is convinced that all these various human motives for
scientific work must exist side by side, even in the same indi-
vidual, and that it is for a university department to present
all of them to its students. But the outstanding fact seems to
be that the work itself should be much the same in all cases,
assuming of course, that actual dishonesty is ultimately as bad
from the commercial point of view as it is from the altruistic,
as bad in practical applications to human physical needs as it
is in philosophical applications to what have been called
human spiritual needs.
Training of Physiological Students — It should be appre-
ciated that physiology articulates intimately both with bio-
logical morphology and with the physical sciences. It is
obvious enough that the processes and reactions of living
things are not to be understood without a certain amount of
morphological or anatomical knowledge. Thus, anatomy and
histology are, in this way at least, and otherwise to some ex-
tent, prerequisite to the study of physiology.
On the other hand, the changes of matter and energy that
go on in living things cannot be seriously studied without a
broad and rather detailed knowledge of the principles ac-
cording to which such changes occur in dead matter. In this
way the field of physiology furnishes opportunity for the
application of physics and chemistry in the understanding of
life. So important is this consideration that physiology may
be defined as the physics and chemistry of living things. This
consideration has not been so generally appreciated as seems
desirable, and many of the present leaders in physiology have
337] , B. E. Livingston 139
first approached the subject through the avenues of mor-
phological study. Perhaps it is because of this that begin-
ners are often led to devote several years to academic work
in morphological pursuits before they are allowed to be-
come acquainted with the physiological aspect of biology, so
that they discover the need of an intimate knowledge of
physics and chemistry only at a rather late stage in their de-
velopment. It is a significant fact that very few of the present
workers in plant physiology have been led to their interest
in the subject from an introductory study of the physical
sciences, although physiology offers some of the most im-
portant physical and chemical problems.
Considering the general applicability of physical as well as
morphological knowledge to physiological study, it is becom-
ing more and more evident that a tyro in physiology should
be encouraged to devote much more attention to physics and
chemistry, in the earlier years of his preparation, than is now
generally the case — which necessarily means that he should
not be encouraged to devote so much time to biological mor-
phology as he does in most institutions where young natural
scientists receive their training.
The considerations just set forth have been given promi-
nence in planning the training leading to the doctorate from
this department, and, while no formal prerequisites are stated,
the need of as much knowledge of chemistry and physics
as the student can obtain is constantly emphasized. At the
same time he is urged to become well acquainted with the
main facts and general principles of animal physiology and
with those of the comparative anatomy and histology of
plants, as thus far available. Since climatic conditions exert
such controlling influences upon the behavior of plants, that
physical branch which is termed climatology must also re-
ceive much emphasis.
It is the general plan of the department to erect no arti-
ficial barriers before the prospective student; the work is so
organized that any person who understands elementary phys-
140 The Department of Plant Physiology [338
ics and chemistry can enter our physiological work. If his
morphological or physical knowledge is inadequate this may
be corrected as his work goes on. In short, an interest in,
and a serious desire to become proficient in, plant physiology
are the only prerequisites for the training that is here offered.
The work of this department has thus far been exclusively
graduate work, so that all of our students are intellectually
rather mature. The scarcity of opportunities for carrying on
advanced work in plant physiology, together with the fact that
numerous educational institutions offer opportunity for ele-
mentary academic courses in this and the related subjects,
have made it appear undesirable to institute undergraduate
courses here. Experience seems to show, furthermore, that
the intellectual power of graduate students is greater among
those who have migrated from one institution to another, than
it is among those who have performed their undergraduate
work in the same institution as that in which graduate work
is undertaken. Whether a causal relation is mainly involved
here is questionable, for the very fact of student migration
generally bespeaks a serious purpose and a definite aim; but
it is also undoubtedly true that student migration tends
strongly to prevent and to obliterate provincial traits of men-
tal character, and to give to the student who has thus
migrated one or more times a more extensive series of in-
terests and a deeper appreciation of relative values.
The general purpose in the training of our students may
be expressed as the inculcation of scholarly habits and of
personal judgment in the carrying out of research. To this
end, the work of the department is carried on as though
research itself — productive scientific study — were the main
aim. The student thus becomes, as it were, an apprentice in
what is planned to be creative physiological endeavor, and he
develops through striving to solve physiological problems
and to interpret and present the results obtained. He is
thus led to read the literature because he seeks the knowl-
edge that it contains, rather than because such reading has
339] B. E. Livingston 141
been assigned or prescribed. He also learns that the plan-
ning and the interpretation of experimental work require far
more serious attention than does the work itself, for a poorly
planned or poorly interpreted piece of work can result in but
mediocre results. The actual operations of experimenta-
tion may be best learned by carrying out a well made plan,
and the interpretation and presentation of the results ob-
tained determine for the most part how valuable they shall
be in the development of the science. Thus as much em-
phasis is placed upon clear imagination,, clear thinking, and
clear presentation, as upon the many details of the manipu-
lation of apparatus, so frequently considered as constitu-
ting scientific knowledge. This department does not aim to
teach the subject, but it carries out investigations and tries
to help the workers to become independent in the planning,
prosecution, and interpretation of research.
A single course of semi-formal lectures, lasting through the
year, with prescribed laboratory experiments, suffices to bring
the students into contact with the various phases of the sub-
ject, and instruction is thereafter mainly personal, in the
form of conferences upon the numerous matters that arise in
the prosecution of research. No attempt is made to stand-
ardize the students beyond the elementary phases of the
subject, but each one is encouraged to develop along line?
determined by its own natural bent. Consequently, problems
for research are not generally "assigned/' as the phrase goes
in many university laboratories, but the prospective investi-
gator is led and assisted to choose a problem according to his
own earlier training and present interest and enthusiasm. An
attempt is made, however, to discourage the taking up of
any problem that does not promise results of a definite nature
which, when they are obtained and interpreted, will surely
fit into the general structure of plant physiology.
It appears probable that the majority of our students will
eventually enter the field of practically applied physiology,
as investigators in agricultural or forestry experiment sta-
tions, or in commercial establishments; but our point of
142 The Department of Plant Physiology [340
view is always that of the pursuit of the science for its own
sake, so that as many as may be needed may find places as
teachers of the subject. For all these lines of endeavor the
same general kind of training appears to be requisite, as has
been pointed out. Such training must aim to make the stu-
dent familiar with the great principles of the science, with
some of the methods employed, and with enough of the lit-
erature so that he may make efficient use of the libraries in
his future work. Above all, he must be led to a facile and
versatile attitude of mind, which regards his science as a con-
tinuously changing thing, with new needs arising at every
turn of its progress; also, he must be not over-timid in fol-
lowing his problem wherever it may lead, even into the fields
of other sciences.
THE WORK so FAR ACCOMPLISHED OR IN PROGRESS
The accomplishment of a scientific research laboratory
should be calculated as the sum of two different terms. The
first of these is, obviously, the progress actually made in in-
vestigation, in the solving of problems, and in contributions
toward what we name the general fund of human knowledge.
The component parts of this term are usually easy of descrip-
tive statement, but difficult of comparative evaluation. The
second term includes what is commonly thought of in uni-
versities as the training of students, but it should also in-
clude the intellectual progress of the laboratory staff itself
(which ought to accumulate to form an asset of some value)
and likewise the aid and encouragement furnished by the
laboratory to persons not directly connected with it at all.
This term, as is readily seen, is the educational one, and its
components are very difficult both of precise description and of
comparative evaluation. Looked at in one way, it may be said
that the first term measures the actual product of the labora-
tory as an institution for the making of knowledge, while the
second measures the preparations made for the accomplish-
ment of future work of many kinds, whether in research or
341] B. E. Livingston 143
other lines of human activity. Both these kinds of effort pro-
gress side by side in the life of every individual and of every
institution; each day is partly devoted to actual accomplish-
ment and partly to preparing for future accomplishments, and
the two sorts of activity cannot be clearly separated. Espe-
cially is this true when it is appreciated that the accomplish-
ment of one worker becomes preparation for the future activi-
ties of others, as well as of the same worker. These two as-
pects of our work may nevertheless be considered separately.
Educational and Preparatory. — Considering the period
from October., 1909, to June, 1917, 38 persons, including the
two members of the staff of the department, have made use
of the laboratory of plant physiology. The periods of use
were : One year for 24 persons, two years for 7 persons, three
years for 5 persons, four years for 1 person, and eight years
for 1 person. Thus, the laboratory has furnished facilities
for mental development, roughly equivalent to those for 65
persons for a single year, or for an average of 8 persons per
year. Ten of the 65 academic years considered are those of
the professor (8) and instructor (2).
Of the 38 individuals who have used the laboratory, four
have worked here after the attainment of the doctor's degree
elsewhere (two of these are on the staff), four have attained
the Ph.D. degree from this university, with Plant Physi-
ology as principal subject, and five others plan to come up
for the degree in June, 1917, with this as their principal sub-
ject. Plant Physiology has been selected as a subordinate
subject (in the requirement for the Ph. D. degree) by 15 per-
sons.
Of the four persons who have received the doctor's degree
from this university, with their main work in this laboratory,
one is now employed in the U. S. Department of Agricul-
ture, two in state agricultural experiment stations, and one
is on the staff of the University of the Philippines. Thus,
three of these have entered applied research and one is de-
voting a portion of his time to teaching.
144 The Department of Plant Physiology [342
The investigation carried on here has itself been largely
preparatory for future work; the problems that we have de-
sired to attack could not be undertaken until the field (which
is a new one) had been specially prepared, so that our con-
tributions to the science are to be regarded largely as begin-
nings and preparations. It appears likely that many of these
lines of work will be carried out elsewhere, either by students
of this university or by others who become interested as the
field is opened. The general nature of our problems will be
touched upon in the following section.
One other feature of the educational and preparatory work
carried on by this department deserves mention, a feature
that may be fully as important as is the direct training of
students. This laboratory has furnished information and ad-
vice to many persons not directly connected with it regard-
ing problems bearing on the water relations of plants, and
has thus been able to render more or less valuable aid to stu-
dents in other institutions and investigators in experiment
stations, etc. To a lesser degree we have been called upon to
aid outside investigators in other fields of plant physiology.
It has been the practice of the department to furnish ideas
and suggestions quite freely to all inquirers, a practice in-
volving the writing of explicit and detailed letters, but one
which seems to be fully as legitimate and valuable as are the
consultations with our own students in residence. It is in-
tended that no such inquiries from outside the depart-
ment shall be subject to neglect or perfunctory reply; such
information and suggestions as we have are furnished
promptly and freely to all who ask. This makes the hand-
ling of the correspondence of the department a somewhat
serious undertaking, but one that is fully worthy of the time
and energy so expended. The number of persons, in many
regions of the world, who are thus more or less indirectly
connected with this laboratory, is much larger than the
number of workers who have actually been in residence here.
Also, the director of this laboratory devotes considerable time
343] B. E. Livingston 145
to the editing of plant physiological papers prepared by work-
ers in other institutions, especially for Physiological Re-
searches, a series of publications with which the University
has no official connection and for which it furnishes no finan-
cial assistance. An English translation of Palladia's Plant
Physiology, with editorial additions, is about to be pub-
lished from this department. It has been prepared from the
German translation of the Sixth Eussian edition, with incor-
poration of the main alterations occurring in the Seventh
Eussian edition.
Contributions to the Science, and Researches Now in Prog-
ress.— To give a clear idea of the nature of the investigations
attempted in this department, it is desirable to present a
brief discussion of the general field in which these investiga-
tions lie. The science of plant physiology deals with the pro-
cesses or changes that go on in living plants. Now, to un-
derstand a change as fully as possible it is required to know
the change first in a roughly descriptive sort of way, after
which our knowledge is to be advanced by consideration of the
dynamic and causal aspects of the process considered. De-
scriptive physiology involves statements of the various sorts
of processes going on in the organism, and it should show in
what regions of the body these changes occur, and when they
occur. Thus, that ordinary green leaves take up the element
carbon out of the air during periods of sunlight is a state-
ment of descriptive physiology, in this sense. To inquire
more deeply concerning this process of carbon-intake clearly
leads to quantitive studies of the various rates at which this
intake may go on, which may be correlated with the various
concomitant conditions of the plant and of its surroundings.
Such studies soon reveal the fact that the rate of carbon-
absorption is determined by a host of conditions, each one of
which requires to be measured with regard to its intensity,
and it is found that the rate in question may assume different
magnitudes as the conditional intensities vary. It is true
that the process of carbon-entrance from the air usually
10
146 The Department of Plant Physiology [344
ceases, and is replaced by one of carbon-exit, when light is
absent, but the same alteration may be induced by many other
changes in the surroundings ; for example, by sufficiently high
or low temperature, by sufficiently low water-content of the
leaves, by a sufficiently high concentration of a poisonous gas
in the air, etc. It soon becomes clear that no physiological
process is to be regarded as at all well understood without a
considerable knowledge of its quantitative control, and dyna-
mic physiology deals with the more elaborate and quantita-
tive statement of the physiological changes thus suggested.
It relates them to their determining conditions within and
without the organism.
From the work of earlier students many plant processes are
now fairly well known in the simple, descriptive way, but none
of these is yet at all well understood in the dynamic or etio-
logical sense. This latter is the phase of physiology which is
now beginning to attract the most serious attention, and to it
will be devoted the energies of investigators for many genera-
tions to come. It is to this field of dynamic physiology that
the researches .of this laboratory are planned to apply.
While descriptive physiology, as above defined, is a compar-
atively old science, dynamic physiology is a young one, and
the problems of the latter are complicated in the extreme —
there are so many different kinds of conditions that may take
part in the control of plant processes, and each of these condi-
tions may be effective with so many different intensities. The
complexity and newness of these dynamic problems explain the
fact that the very methods needed for the sort of study here
suggested are, for the most part, still to be devised. It is ob-
vious that dynamic physiological investigations must rest upon
comparative measurements of the intensities of effective condi-
tions and of the concomitant or resulting rates of the processes
that are to be investigated, so that studies of the possible ways
by which such measurements and comparisons may be made
must constitute the beginnings in this field. All of our work
has aimed at this causal sort of explanation of process rates,
345] B. E. Livingston 147
but much of it, as so far carried out, has resulted in little
more than giving us certain methods of study and certain
incomplete results. The problems are so complex that broad
generalizations cannot be looked for for a long time.
It has so happened that two phases of dynamic physiology
have thus far occupied much of our attention, as far as
research is concerned. At the same time, these two phases are
among the most fundamental of all, as regards plant growth
in general, and the agricultural and forestal production of
plant material in particular, and they also appear to repre-
sent the very simplest problems in plant control. The first
of these phases, or groups of dynamic problems, deals with
the water relations of plants; the second deals with their
inorganic-salt relations. The connotation of these two groups
of problems may be roughly suggested to the reader by the
statement that the agricultural operations of drainage and
irrigation are related to plant water relations, while fertilizer
practice is related to inorganic-salt relations. A large number
of the contributions from this laboratory have dealt with one
or the other of these general phases. The measurement and
experimental control of the environmental conditions of mois-
ture and of inorganic salts, and the relation of these condi-
tions to plant growth, have thus received a large portion of
our attention.
Along with the study of external conditions, the internal
conditions of our experimental plants must, of course, receive
consideration. While these conditions are generally much more
difficult of adequate measurement than are those of the en-
vironment, some progress has nevertheless been made in this
direction. For example, the work of this laboratory has
aided the advance of our knowledge of the manner in which
internal conditions control the rate of water-loss from plant
leaves, a very important subject, both to the science of plant
physiology and to the arts of agriculture and forestry.
The relations of temperature and of oxygen supply have
recently begun to receive attention here, as well as the light
148 The Department of Plant Physiology [346
relation (besides its consideration as a term in the water-
relation). The complex relation holding between plant
growth and what is generally understood by the vague word
climate, also enters into some of our more recent undertakings.
This is not the place to attempt a presentation of the de-
tailed results so far obtained in the research work of the Lab-
oratory of Plant Physiology, although it may be remarked that
some apparently valuable results have already rewarded our
efforts. What most requires emphasis here is, however, that a
large amount of necessary preparation has been accomplished,
getting ready for rational experimentation in the future.
Many new methods of operation and of interpretation have
oeen evolved, and it appears as though the time may not be
remote when some of the broader aspects of the conditional
control of plant activities may be undertaken with some prom-
ise of a satisfactory outcome. Such broader problems will
probably have to be left to other, institutions, with more facili-
ties and larger appropriations than are now generally avail-
able for university laboratories.
To summarize the last few paragraphs, our operations have
been and are directed toward a dynamic analysis of plant
activity. The point of view here employed may perhaps be
envisaged if the reader will regard the living plant in some-
what the same general way as he might any complex machine,
such as a gasoline motor, for example. To understand its
working one must understand how and how much various con-
ditions may affect such a machine; in short, he must become
an engineer with respect to that particular mechanism. Dyna-
mic plant physiology may be said, then, to be engineering sci-
ence as applied to the operations of the living plant. It can
progress only through quantitative studies, — through experi-
mental tests under controlled or measured conditions, through
the comparison of efficiency graphs and curve-tracings made
by recording instruments, through the mathematical interpre-
tation of relations between conditions and process rates,
etc., — and it is with just this sort of studies that our inves-
tigations have to do.
347]
B. E. Livingston
149
150 The Department of Plant Physiology [348
The following paragraphs present the main contributions
thus far made by this laboratory.
The water relation of plants. — This relation involves the
plant responses that result from alterations in the supply and
in the consumption or loss of water. For temperate regions it
is the main conditional relation for plant growth in the open,
whether the plants be wild or cultivated. Most of the water
necessary for plant growth is given off into the air, by evap-
oration from the plant surfaces, almost as soon as the water is
taken up from the soil ; the amount of this liquid actually con-
sumed in forming the plant body is very small. Active plants
must be continuously impregnated with water, and the loss by
evaporation may be likened to a very considerable but unavoid-
able leak in a steam engine. The rate of water supply to the
plant must be great enough to counterbalance this loss by
evaporation, or the growth process will be retarded. To
understand the plant as a machine it is thus primarily neces-
sary to study the conditions that control the rates of water-
loss and of water-intake.
One of the principal conditions that affect the rate of
water-loss by evaporation from plants is the evaporating
power of the air, and this condition needs to be studied quan-
titatively. To accomplish this the porous-cup atmometer has
been devised and perfected during the last decade, most of the
work having been done in connection with this laboratory.
The instrument, in various forms, is now widely employed by
students of plant growth. The readings obtained by its
means may be regarded as measures of the evaporating power
of the air and they may be obtained for any desirable time
intervals.
Another condition that takes part in the control of the rate
of water loss from plants is the intensity of absorbed radiant
energy, received directly or indirectly from the sun. It is
therefore requisite to measure and integrate this intensity as
it affects the evaporation of water from moist surfaces such as
plant leaves. This is now possible by the use of the radio-
349] B. E. Livingston 151
atmometer, which has also been devised and perfected here,
and this apparatus is likewise coming into general use.
The two conditions just mentioned are both effective from
without the plant; they are external conditions. There is also
an internal condition (effective from within the plant) that
exerts great influence upon the rate of evaporational water-
loss from plant surfaces., and this has been called, in our dis-
cussions, the transpiring power of the plant. Studies largely
carried out in this laboratory have resulted in the perfection
of methods by which the intensity of this internal condition
may be evaluated, and integrated over convenient time periods.
Reference is here made to the method of relative transpiration
and to that of cobalt-chloride paper. Both are now frequently
employed in studies of plant growth.
As has been mentioned,, the rate of water-supply to the
plant also requires attention in studies of the water relations.
This is primarily the water-supplying power of the soil,
another external condition. The need for quantitative study
of this has led to investigations in the realm of soil physics,
and our efforts have already resulted in some useful methods
of approach, but more work will be necessary before we can
deal with this subterranean condition as satisfactorily as is
now possible with the conditions that are effective above the
soil. Out of our work has come the auto-irrigator, an instru-
ment which maintains the moisture conditions of the soil
nearly constant throughout long periods of time. Its readings
indicate the rates at which an experimental plant removes
water from a soil mass thus automatically supplied with
water. The auto-irrigator is now employed by many experi-
menters, in cases where it is desired to maintain a constant
soil-moisture content. Soil osmometers have also been em-
ployed in the study of the water-supplying power of the soil as
related to absorption by plant roots.
By the employment of these various methods, all perfected
here within the last few years, we have been able to begin to
understand some of the more fundamental features of the
152 The Department of Plant Physiology [350
plant water relation, and the near future promises much
greater advances.
The inorganic salt relation of plants. — This relation involves
the plant responses that result from alterations in the supply
and in the consumption or loss of inorganic salts. So far as
studies of this relation have progressed, these have dealt
mainly with the power of the surroundings to deliver inor-
ganic salts (or the ions into which they dissociate) to plant
roots, as this power is related to growth. This aspect of this
relation has formed the subject of very many experimental
investigations during the past century, but the work of this
laboratory has approached the problem from a somewhat new
point of view.
The soil presents such a very complicated physical and
chemical system that it is quite hopeless, for the present, to
attempt to understand the behavior of soil salts in any way
adequate to the needs of plant physiology, and our attention
has been turned exclusively to the study of plant growth in
nutrient solutions and in sand cultures. For the growth of
ordinary plants it requires only seven ions of inorganic salts
to produce satisfactory growth, these being: potassium (K),
calcium (Ca), magnesium (Mg), iron (Fe), nitrate (No3),
sulphate (S04), and phosphate (P04). Iron is needed in
relatively but very small "amount, it being only necessary that
the solution bathing the plant roots shall contain a trace of
this ion. Variations in the partial concentrations, or in the
supply, of the other six ions may produce marked alterations
in growth, however, and it is with reference to these that our
work was begun. By means of elaborate series of different
culture solutions the effects upon the plant, of altering the salt
proportions in the nutrient medium, have been experimentally
studied. It has been possible to devise a 3-salt nutrient solu-
tion for use as a standard, in which the three salts (CaN03;
MgS04 and KH2P04) are present in proper proportions to
produce a physiologically balanced solution, producing excel-
lent growth. The proper salt proportions for any plant form,
351] B. E. Livingston 153
and for any given complex of external conditions may readily
be determined. All the various standard nutrient solutions
heretofore employed have contained at least four salts (besides
the trace of iron), and have been correspondingly more com-
plex and difficult to handle and interpret. This work applies
to many phases of the art of fertilizer practice, as employed in
agriculture, and it furnishes a method by which we may now
begin to study the salt relation as influenced by the condi-
tions of the water relation, the temperature relation, etc.
The effects of some other inorganic ions upon plants have
begun to receive attention here, also the effects of variations
in the oxygen content of the soil.
The relation of plants to climatic conditions. — The main
climatic conditions that affect plants are air temperature,
atmospheric evaporating power, and the effective intensity If
solar radiation. Other climatic -conditions generally affect
plants only indirectly; for example, rainfall influences the
water-supplying power of the soil.
The studies thus far undertaken in this laboratory have
dealt with an attempt to find out in what manner and to what
degree the annual march of the complex of climatic condi-
tions may be related to the corresponding annual or seasonal
march of plant growth-rates. From these studies has been
developed -a method by which it appears possible to compare
climates (of different places at the same time or of the same
place at different times) in terms of the growth-rates of a
standard plant. The plant is thus employed as an auto-
matically weighting and integrating instrument.
This general relation is of great importance to agriculture
and forestry and the point of view here taken (that of the
conditional control of plant processes) is attracting the atten-
tion of investigators in these subjects. The problems are
exceedingly complex, but progress is being slowly made.
The reader will be able to form a somewhat more concrete
conception of what has thus far been accomplished, by refer-
ence to the list of publications from this department, which
follows the present paper.
154 Publications from the Laboratory [352
LIST OF PUBLICATIONS FROM THE LABORATORY OF
PLANT PHYSIOLOGY
October, 1909, to February, 1917.
(Arranged by years, the year beginning October 1.)
1909-1910
BROWN, W. H., and L. W. SHARP, The closing response in Dionaea.
Bot. Gaz. 49: 290-302. 1910.
HAWKINS, LON A., The porous clay cup for the automatic watering
of plants. Plant World 13: 220-227. 1910.
LIVINGSTON, B. E., The heath of Ltineburg. Plant World 12: 231-
237. 1909.
A rain-correcting atmometer for ecological instrumentation.
Plant World 13: 79-82. 1910.
— Operation of the porous cup atmometer. Plant World 13: 111-
118. 1910.
Evaporation and other climatic factors in relation to the distri-
bution of plants. Carnegie Inst. Wash. Year Book 8: 62. 1910.
Atmometry and the relation of evaporation to other factors. Car-
negie Inst. Wash. Year Book 8: 62. 1910.
The physics of transpiration in plants. Carnegie Inst. Wash .
Year Book 8: 62. 1910.
Soil-moisture in relation to plant growth. Carnegie Inst. Wash.
Year Book 8: 63. 1910.
1910-11
BROWN, W. H., Evaporation and plant habitats in Jamaica. Plant
World 13: 268-272. 1910.
LIVINGSTON, B. E., Relation of soil moisture to desert vegetation.
Bot. Gaz. 50: 241-255. 1910.
A radio-atmometer for comparing light intensities. Plant World
14: 96-99. 1911.
The relation of the osmotic pressure of the cell sap in plants to
arfd habitats. Plant World 14: 153-164. 1911.
— Evaporation and soil moisture. Carnegie Inst. Wash. Year Book
9: 58-59. 1911.
1911-12
BROWN, W. H., The relation between soil moisture content and the
conditions of the aerial environment of plants at the time of
353] of Plant Physiology 155
wilting. (Preliminary abstract.) Johns Hopkins Univ. Circ.
whole number 242: 26-28. 1912.
BROWN, W. H., The relation of evaporation to the water content of
the soil at the time of wilting. Plant World 15: 121-134.
1912.
JONES, W. R., The digestion of starch in germinating peas. (Pre-
liminary abstract.) Johns Hopkins Univ. Circ. whole number
242: 29-30. 1912.
-Same title. Plant World 15: 176-182. 1912.
LIVINGSTON, B. E., The new laboratory of plant physiology at Home-
wood. Johns Hopkins Univ. Circ. whole number 242: 7-10.
1912.
— The resistance offered by leaves to transpirational water loss.
(Preliminary abstract.) Johns Hopkins Univ. Circ. whole
number 242: 11-13. 1912.
— Present problems in soil physics as related to plant activities.
Amer. Nat. 66: 294-301. 1912.
The choosing of a problem for research in plant physiology.
Plant World 15: 73-82. 1912.
— A schematic representation of the water relations of plants, a
pedagogical suggestion. Plant World 15: 214-218. 1912.
— — A rotating table for standardizing porous cup atmometers.
Plant World 15: 157-162. 1912.
- —Incipient drying in plants. (Abstract.) Science n. s. 35: 394-
395. 1912.
— Evaporation and soil-moisture. Carnegie Inst. Wash. Year Book
10: 64-65. 1912.
LIVINGSTON, B. E., and A. H. ESTABEOOK. Observations on the degree
of stomatal movement in certain plants. (Preliminary ab-
stract.) Johns Hopkins Univ. Circ. whole number 242: 24-25.
1912.
— Same title. Bull. Torr. Bot. Club 39: 15-22. 1912.
LIVINGSTON, B. E., and F. SHEEVE. The relation between climatic con-
ditions and plant distribution in the United States. Johns
Hopkins Univ. Circ. whole number 242: 19-20. 1912.
SHEEVE, EDITH B., A calorimetric method for the determination of
leaf temperatures. Johns Hopkins Univ. Circ. whole number
242: 36-38. 1912.
LIVINGSTON, B. E., and W. H. BEOWN. Relation of the daily march of
transpiration to variations in the water content of foliage
leaves. (Preliminary abstract.) Johns Hopkins Univ. Circ.
whole number 242: 21-23. 1912.
— Same title. Bot. Gaz. 53: 309-330. 1912.
HAWKINS, LON A. The effect of certain chlorides, singly and combined
in pairs, on the activity of malt diastase. (Preliminary ab-
156 Publications from the Laboratory [354
stract.) Johns Hopkins Univ. Circ. whole number 242: 34-35.
1912
1912-13
BROWN, W. H., The relation of the substratum to the growth of
Elodea. Philippine Jour. Sci. 8: 1-20. 1913.
CALDWELL, J. S., The relation of environmental conditions to the
phenomenon of permanent wilting in plants. Physiol. Res. I :
1-56. 1913. (Work done at Desert Laboratory, directed by
B. E. Livingston.)
HARVEY, E. M., The action of the rain-correcting atmometer. Plant
World 16: 89-93. 1913. (Work done at Desert Laboratory,
directed by B. E. Livingston.)
HAWKINS, LON A., The effect of certain chlorides, singly and com-
bined in pairs, on the activity of malt diastase. Bot. Gaz.
55: 265-285. 1913.
The influence of calcium magnesium and potassium nitrates upon
the toxicity of certain heavy metals toward fungus spores.
Physiol. Res. 1 : 57-91. 1913.
HOYT, W. D., Some toxic and antitoxic effects in cultures of Spiro-
gyra. Bull. Torr. Bot. Club 40: 333-360. 1913. (Edited by
B. E. Livingston.)
LIVINGSTON, B. E., The resistance offered by leaves to transpiration-
al water loss. Plant World 16: 1-35. 1913.
Adaptation in the livir^ and non-living. Amer. Nat. 47: 72-82.
1913.
Osmotic pressure and related forces as environmental factors.
Plant World 16: 165-176. 1913.
Climatic areas of the United States as related to plant growth.
Proc. Amer. Phil. Soc. 52: 257-275. 1913.
The water relations of plants. Carnegie Inst. Wash. Year Book
II: 60-61. 1913.
1913-14
HOYT, W. D., Some effects of colloidal metals on Spirogyra. Bot.
Gaz. 57: 193-212. 1914. (Edited by B. E. Livingston.)
LIVINGSTON, B. E., The water relations of plants. Carnegie Inst.
Wash. Year Book 12: 77-79, 1914.
LIVINGSTON, B. E., and GRACE J. LIVINGSTON. Temperature coeffi-
cients in plant geography and climatology. Bot. Gaz. 56: 349-
375. 1913.
SHIVE, J. W., and B. E. LIVINGSTON. The relation of atmospheric
evaporating power to soil moisture content at permanent
wilting in plants. Plant World 17: 81-121. 1914.
TOTTINGHAM, W. E., A quantitative chemical and physiological study
of nutrient solutions for plant cultures. Physiol. Res. I :
133-245. 1914.
355] of Plant Physiology 157
1914-15
FBEE, E. E., A relative score method of recording comparisons of
plant conditions and other unmeasured characters. Plant
World, 18: 249-256. 1915.
^LIVINGSTON, B. E., Atmometry and the porous cup atmometer. Plant
World 18: 21-30, 51-74, 95-111, 143-149. 1915.
A modification of the Bellani porous plate atmometer. Science
n. s. 41: 872-874. 1915.
^ Atmospheric influence on evaporation and its direct measure-
ment. Monthly Weather Rev. 3: 126-131. 1915.
Spherical porous cups for atmometry. Carnegie Inst. Wash.
Year Book 13: 84-85. 1915.
LIVINGSTON, B. E., and LON A. HAWKINS. The water-relation be-
tween plant and soil. Carnegie Inst. Wash. Pub. 204: 1-48.
1915.
„ LIVINGSTON, B. E., and ALEITA HOPPING. Permanent standardiza-
tion of cobalt-chloride paper for use in measuring the tran-
spiring power of plant surfaces. Carnegie Inst. Wash. Year
Book 13: 87. 1915.
x- LIVINGSTON, B. E., and A. L. BAKKE. The transpiring power of plant
foliage, as measured by the method of standardized hygromet-
ric paper. Carnegie Inst. Wash. Year Book 13: 86-87. 1915.
LIVINGSTON, B. E., and J. W. SHIVE. The non-absorbing atmometer.
Carnegie Inst. Wash. Year Book 13: 83-84. 1915.
Relation between atmospheric conditions and soil moisture con-
tent at permanent wilting of plants. Carnegie Inst. Wash.
Year Book 13: 86. 1915.
LIVINGSTON, B. E., and H. C. SAMPSON. Atmometric units. Carnegie
Inst. Wash. Year Book 13: 85. 1915.
^LIVINGSTON, B. E., and LON A. HAWKINS. The water-attracting pow-
er of soil, as measured by the rate of loss for the auto-irri-
gator. Carnegie Inst. Wash. Year Book 13: 86. 1915.
LIVINGSTON, B. E., and H. E. PULLING. The water-supplying power
of the soil. Carnegie. Inst. Wash. Year Book 13: 86-87. 1915.
McLEAN, F. T., Relation of climate to plant growth in Maryland.
Monthly Weather Rev. 43: 65-72. 1915.
PULLING, H. E. and B. E. LIVINGSTON. The water-supplying power
of the soil as indicated by osmometers. Carnegie Inst. Wash.
Pub. 204: 51-84. 1915.
SHIVE, J. W., The freezing points of Tottingham's nutrient solutions.
Plant World 17: 345-353. 1915.
An improved non-absorbing porous cup atmometer. Plant World
18: 7-10. 1915.
158 Publications from the Laboratory [356
SHIVE, J. W., A three-salt nutrient solution for plants. Amer. Jour.
2: 157-160. 1915.
1915-16
BAKKE, A. L., and B. E. LIVINGSTON. Further studies on foliar tran-
spiring power in plants. Physiol. Res. 2: 51-71. 1916.
FREE, E. E., An ancient bajada of the Great Basin region. Carnegie
Inst. Wash. Year Book 14: 95. 1916.
FREE, E. E., and B. E. LIVINGSTON. The relation of soil aeration to
plant growth. Carnegie Inst. Wash. Year Book 14: 60-61.
1916.
JOHNSTON, E. S., and B. E. LIVINGSTON. Measurement of evapora-
tion for short time intervals. Plant World 19: 119-150.
1916.
LIVINGSTON, B. E., Physiological indices of temperature efficiency
for plant growth. Carnegie Inst. Wash. Year Book 14: 61-62.
1916.
— A simple climatic index. Carnegie Inst. Wash. Year Book 14:
62. 1916.
— Plane porous clay surfaces for use in atmometry. Carnegie
Inst. Wash. Year Book 14: 76. 1916.
Auto-irrigation of pots of soil for experimental cultures. Car-
negie Inst. Wash. Year Book 14: 76. 1916.
— Physiological temperature indices for the study of plant growth
in relation to climatic conditions. Physiol. Res. 1 : 399-420.
1916.
* A single index to represent both moisture and temperature con-
ditions as related to plant growth. Physiol. Res. 1 : 421-440.
1916.
— A record of the doctors in botany of the University of Chicago,
1897-1916. Presented to John Merle Coulter, Professor and
head of the Department of Botany, by the Doctors in Botany,
at the Quarter-Centennial of the University, June, 1916. vii
+ 87 p. Chicago, 1916. (Edited by B. E. Livingston.)
LIVINGSTON, B. E., and E. S. JOHNSTON. Influence of solar radia-
tion as a drying agent. Carnegie Inst. Wash. Year Book 14:
75. 1916.
McCATj,, A. G., A new method for the study of plant nutrients in
sand cultures. Jour. Amer. Soc. Agron. 7: 249-252. 1915.
The absorption by soils of potassium from aqueous solution of
potassium chloride. Carnegie Inst. Wash. Pub. 230: 167-175.
1915.
— A method for the renewal of plant nutrients in sand cultures.
Ohio Jour. Sci. 16: 101-103. 1916.
357] of Plant Physiology 159
McCALL, A. G., The availability of nutrient salts. Jour. Amer. Soc.
Agron. 8: 47-50. 1916.
Field and laboratory studies of soils, viii + 133 p., 54 figs.
New York, 1916.
McCALL, A. G., F. M. HILDEBEANDT and E. S. JOHNSTON. The ab-
sorption of potassium by the soil. Jour. Phys. Chem. 20:
51-63. 1916.
SHAW, C. F., and E. E. FEEE. Agronomic and soil conditions in the
Selby Smoke Zone. U. S. Bur. Mines, Bull. 98: 451-473.
1915.
SHIVE, J. W., A study of physiological balance in nutrient media.
Physiol. Res. I: 327-397. 1915.
TEELEASE, S. F., and B. E. LIVINGSTON, Foliar transpiring power
and the Darwin and Pertz porometer. Carnegie Inst. Wash.
Year Book 14: 76-77. 1916.
• The daily march of transpiring power as indicated by the por-
ometer and by standardized hygrometric paper. Jour. Ecol.
4: 1-14. 1916.
1916-17
CANNON, W. A. and E. E. FEEE. The ecological significance of soil
aeration. Science n. s. 45: 178-180. 1917.
FEEE, E. E., An ancient lake basin on the Mohave river. Carnegie
Inst. Wash. Year Book 15: 90-91. 1917.
Underground structure and artesian water in desert valleys of
the Great Basin. 'Carnegie Inst. Year Book 15: 91-94. 1917.
LIVINGSTON, B. E., A quarter-century of growth in plant physiology.
Plant World 20: 1-15. 1917.
The laboratory of plant physiology. Johns Hopkins Univ. Circ.,
whole number 290: 40-45. 1916.
LIVINGSTON, B. E., and E. E. FEEE, Relation of soil aeration to plant
growth. Carnegie Inst. Wash. Year Book 15: 78. 1917.
LIVINGSTON, B. E., and EDITH B. SHEEVE, Improvements in the meth-
od for determining the transpiring power of plant surfaces
by hygrometric paper. Plant World 19: 287-309. 1916-
LIVINGSTON, B. E., and F. SHEEVE, The role of climatic factors in
determining the distribution of vegetation in the United
States. Carnegie Inst. Wash. Year Book 15: 69-72. 1917.
PULLING, H. E., The angular micrometer and its use in delicate and
accurate microscopic measurements. Amer. Jour. Bot. 8:
393-406. 1916.
160 Atmometric Units [358
ATMOMETRIC UNITS
BY BURTON" E. LIVINGSTON
The increasing interest in atmometry 1 and the fact that
this subject is becoming recognized as of general and funda-
mental importance in many branches of scientific and practical
endeavor, make it desirable that there be some uniformity in
our conceptions as to the units employed in atmometric meas-
urements. To approach the subject it is first necessary that
the purpose of atmometric observations be clearly in mind;
much vagueness still prevails in this connection. The rate
of evaporation of water from any surface is dependent on
two sets of conditions. One set (internal ones) are effective
in or behind the surface and the other (external ones) are
effective in front of the surface, that is, in the gas phase of
the system. The internal conditions are the characteristics
of the evaporating surface and include such features as the
concentration of solutes in the liquid water, the influence ex-
erted by the presence of a solid in which the water is imbibed,
the shape and extent of the surface, its direction of exposure,
its ability to absorb or emit radiant energy, the heat-conduct-
ing capacity of the material back of the surface, etc. The
external conditions include primarily four characteristics of
the space in front of the evaporating surface : the temperature
of the gas phase, its moisture condition, the influence of move-
ment or circulation of the gas over the surface, and the effec-
tive intensity of impinging radiation. I have used the term
1 1 employ the word as synonymous with and shorter than atmid-
ometry, just as I have adopted atmometer in place of its rival, atmid-
ometer. Both are etymologically correct, but the one formed from
the root atmo, besides being shorter, has received the sanction of an
international meteorological congress. Atmometer seems to have
been coined by Sir John Leslie, 1813. (See Livingston, B. E.,
" Atmometry and the porous cup atmometer." Plant World 18: 21-30,
51-74, 95-111, 143-149. 1915. Other papers are there cited.)
359] B. E. Livingston 161
evaporating power of the air to include the first three of these,
since the gas phase is air in most studies and since these three
features are properties of this gas. The fourth feature de-
pends only indirectly, and to a comparatively slight degree,
upon the characteristics of the gas phase next to the evaporat-
ing surface. In climatological atmometry this is the effective
intensity of solar radiation, direct or indirect, which depends
upon the season, the time of day and the state of the sky, as
well as upon the nature of reflecting surfaces in the vicinity.
Since evaporation is a process and not a state of matter, its
magnitude has to be expressed in terms of time rates. While
temperature, for instance (being a state of matter), may be
expressed in degrees on a thermometer scale, evaporation in-
tensities must be stated as the amount of water evaporated
in a unit of time. Atmospheric evaporating power refers
to the external surroundings of the evaporating surface (usu-
ally to the air space above it, about it, etc.) and it need not
specifically refer to the air itself, for if there were no air
present this space would still possess an evaporating power.
The evaporating power of the air over a surface is considered
as proportional to the reciprocal of the tendency of all the
conditions effective in the space over that surface to resist the
vaporization of water therefrom.
There have been some who have objected to this expres-
sion, but they have not put forward another term. From a
long-continued attempt to acquire modes of expression by
which we may hope to deal with the dynamic aspect of plant
and animal environments an alternative expression has devel-
oped, which may be brought forward here.
In all considerations of the dynamic relations between or-
ganisms and their surroundings we find it valuable to con-
sider the internal and the external complexes of influential
conditions separately, and each group of conditions may be
expressed, for any process we may have to deal with, as a
single value or index. We may thus speak of the index of
transpiring power, the index of environmental radiation, and
11
162 Atmometric Units [360
the index of the evaporating power of the air. From this last
expression comes the new term, the atmometric index of the
locality and time period considered.
The atmometric index is the relative measure of the evapo-
rating power of the air, and it is to be expressed as a possible
time rate of doing work ; it is an index of a power. The unit
of measurement must therefore be a unit of work, but it may
just as well be a unit of process rate, if the same process be
always employed. Thus it may be stated as the amount of
water evaporated per unit of time. If the liquid water were
always at the same temperature this would actually be a
measure of work. That the water of evaporating surfaces
varies in temperature has been thus far neglected in this
whole line of enquiry, the errors thus arising being relatively
small in the present early stages of our studies.
To determine the numerical value of the atmometric index,
we must also consider a factor representing some standard unit
of surface. It has been seen above that the power of any sur-
face to give off water vapor is determined by the character-
istics of that surface, and that the extent of the surface is not
by any means the only characteristic that needs to be con-
sidered. The shape and the direction of exposure of the sur-
face must be taken into account, and also the influence of the
non-aqueous materials that are in or behind the surface, etc.
It is- therefore impossible to employ a surface unit defined by
area alone. As soon as this is realized all attempts to ex-
press the atmometric index as a time rate of evaporation from
a square centimeter (etc.) of free water surf ace .are seen to be
quite useless. A free water surface is more or less nearly
plane and more or less nearly horizontal (depending upon the
wind velocity, among other things), but it may be of any
shape or size, and all these characteristics are important.
With a given set of aerial conditions two different atmometer
pans, for instance, can give off the same amount of water per
hour, per square centimeter of surface, only when they are of
the same size and shape. Also, the depth of the water and
361] B. E. Livingston 163
the nature of the pans themselves must be exactly alike. It
is thus both theoretically and practically impossible to express
the surface factor in the atmometric index by a unit that rep-
resents merely extent of surface.
Since the complex of internal conditions that make up the
capacity of any surface to produce evaporation is very difficult
of analysis, we may avoid the necessity of this analysis by
simply using atmometer surfaces that act alike. Then the
surface factor of our unit of measurement becomes the surface
of our instrument (with whatever characteristics it may have),
and we do not need to enquire what may be its area, etc. In all
the studies so far carried out with porous clay and paper sur-
faces for measuring the evaporating power of the air, I have
never been led to determine the area of the surface employed ;
it would have been useless to do so, although such a surface
is easily measured. We are thus led to the proposition that
the atmometric index is to be expressed in terms of (1) a
weight unit of water, (2) a time unit, and (3) a given stan-
dard instrument. All these desiderata are supplied in such
a statement as this : that the evaporating power of the air in
a given locality and for a given period is such as to produce
the evaporation of so and so many grams of water per hour
from a standard spherical porous-cup atmometer. . No unit of
area is considered, although all the internal characteristics of
the instrument are implied by its name.
It is clear that it makes no difference what sort of surface
we may use as standard, but we must use the same standard
throughout any series of comparative measurements, and when
several instruments are needed we must be sure that their in-
ternal characteristics are as nearly alike as possible, as far as
these characteristics may influence the rate of evaporation.
The only feasible way to compare a number of instruments
in this last regard is to place them all in the same environ-
ment (as far as environmental characteristics may influence
the rate of evaporation) and then compare their evaporation
rates. If these rates differ this must be because of internal
164 Atmometric Units [362
differences in the instruments. That two porous cups or
pans of water are of t'he same size, shape, color, etc., does not
necessarily indicate that they may be expected to give like
readings if placed in the same environment, for other, less
easily recognized characteristics of the instruments may not
be without influence, and the surfaces may differ with respect
to some of these. This consideration leads to standardization
and the use of a rotating table.
By this procedure an index is obtained that represents rela-
tive capacity of each of the instruments tested, to give off
water vapor, and the index of each one is expressed as a
coefficient of correction, a number by which the readings of
that instrument are to be multiplied in order to give the read-
ing that would have been obtained from the master standard
instrument if it had been operated for the same time and at
the same place. If an instrument is effectively just like the
master standard its coefficient is unity. It is not possible,
however, to obtain useful coefficients for instruments that
differ appreciably from the standard in form, size, etc.
Since it is necessary that several instruments be practically
alike if their readings are to be comparable, it is highly desir-
able that different workers use as few different forms of instru-
ment as possible. For studies on the details of the evaporation
process itself various kinds of surfaces are desirable, but for
general climatic atmometry the number of kinds should be
kept as small as may be. This seems to be not at all well
understood, and workers who have not taken the trouble to
appreciate just what is the purpose of atmometric measure-
ments continue to construct new types of instruments and to
employ them. For example, the idea is abroad that if the
right sort of instrument might be devised its readings would
indicate relative rates of plant transpiration. Obviously such
an instrument would have to alter its internal conditions from
minute to minute, just as would occur in the standard plant
individual, and all other plants would usually differ from it.
The idea is bootless. We do not wish to measure plant tran-
363] B. E. Livingston 165
spiration but to measure the atmometric index of the air in
terms of its effect upon a standard instrument whose internal
conditions do not change. The internal conditions of each
plant or group of plants must be studied in relation to the un-
changing ones of the instrument. A given temperature change
does not affect all objects or processes alike, yet we do not con-
struct a new thermometer scale for each object or process with
which we deal. It may be well to mention in this connection
that atmometry should furnish climatological data applicable
to many fields of endeavor ; the animal ecologist requires these
data as much as does the plant ecologist, and irrigation en-
gineers and students of atmospheric hygiene and ventilation
all have use for atmometric measurements.
In choosing the instrument to be used the first condition
to be met is that its internal conditions or characteristics
should not alter; they should be uninfluenced by changes
in the surroundings, for it is changes in the latter that we wish
to measure. This requirement immediately excludes all forms
of free water surfaces, since they alter with wind, etc. Never-
theless, since an open pan of water is the from of atmometer
employed by the U. S. Weather Bureau, since this is the sim-
plest form of instrument that is useful in any way, and since
data obtained with this pan will surely prove of much greater
value than no atmometric data at all, the pan of water must be
accepted as the crudest and most imperfect form of atmome-
ter. It should be added that if pans of water are used they
should generally be of the same form, size, etc., as the stand-
ard recently adopted by the U. S. Weather Bureau. If this be
adhered to, all pan measurements will be comparable among
themselves and with the Weather Bureau data, as far as this is
possible with that general class of instruments.
The second requirement for an evaporating surface is that
it should be as sensitive to all the effective conditions of the
surroundings as is possible, without any alteration in its in-
ternal characteristics. It should therefore be a surface that
is freely exposed to wind action. A nearly ideal surface would
166 Atmometric Units [364
be that of a small, spherical droplet of water suspended freely
in the air. This is not practicable, but the Livingston stan-
dard spherical porous cup seems to approach this desideratum
as nearly as is possible when general ease of manipulation is
considered. Since we have been able to obtain these porcelain
spheres I have regarded the quest for a practically perfect
surface as at an end. Some form of imbibed porous surface
is undoubtedly best for general purposes, and students of
ecology, ventilation engineers, agriculturists, etc., should
avoid the free water surface if possible, unless it is desired that
the results obtained be roughly comparable with those obtained
by the Weather Bureau.
A third requirement is not as important now as it will be
later, after more atmometric data have been collected. This
is, that the instrument should be like some form previously
used, so as to give data that may be comparable with at least
some of those already on record.
Of the different forms of imbibed porous surface there are
four that should be more or less generally useful : the Piche
paper disk, the Bellani porous clay disk, the Babinet cylinder
and the Leslie sphere, the last three having been recently im-
proved in our own work. Probably more measurements have
been made with the Piche paper disk and with the Livingston
standard cylinder than with any other types of instrument,
but the Piche instrument has serious practical shortcomings
and the sphere is more nearly perfect than the cylinder. The
cylinder will remain an important instrument for a long time
but the sphere will almost surely .replace it eventually. A
fourth feature of the porous sphere may be emphasized as
desirable, namely, the ready applicability of this type of in-
strument to the measurement of effective radiation intensity,
which is the other aerial condition of evaporation besides the
evaporating power of the air. Since we have been able to
obtain black porous spheres of the same size as the white ones,
the spherical form has become almost essential in all work in
atmometry involving radiation. The two spheres, one white
365] B. E. Livingston 16'7
and one black, when operated together, make up the radio-
atmometer, for use in studies of radiation as an atmometric
condition.
Whatever type of evaporating surface is employed, this sur-
face must be clearly defined, so that the data obtained will not,
by any chance, be regarded as comparable with other data
derived from another type of surface. This means that the
essentials of the instrument must be described, but this can
be accomplished by merely naming the instrument and refer-
ring to some previous description. Thus, it may be stated
that a given set of data were obtained by means of the U. S.
Weather Bureau pan, the Briggs and Shantz shallow pan,
the Livingston standard sphere, etc. If a new type of in-
strument has to be used it requires a complete description.
In stating the amount of water lost from the given instru-
ments during a unit of time, it is of course unimportant what
water unit is employed, so long as it is definite enough for the
work in hand. Since the whole aim of atmometry is to meas-
ure a power to do work, and since the amount of liquid water
vaporized per unit of time is considered as a measure of this
power, weight units rather than volume units should be used.
Nevertheless, if the temperature does not vary too much, from
reading to reading, and generally if there is no need for ex-
treme precision, volume units may be used, and we may con-
sider that a cubic centimeter of water weighs a gram.
Obviously, the volume or weight of water lost from a certain
type of instrument for a unit of time may always be multiplied
by any value that the worker may like, so long as this value
is stated, and so long as it is always applied to all readings
from this same type of instrument. This treatment does not
alter the relative values of a series of comparable readings and
the results remain comparable. This principle makes it logi-
cal to use depth units instead of volume units, for free water
surfaces, for the depth of water lost from a given cylindrical
pan is the volume lost, multiplied by the reciprocal of the sur-
face area, this coefficient being a constant for the instrument.
168 Atmometric Units [366
With open pans it is easier to measure depth than volume, for
rough approximations. It is true that volume or weight read-
ings from other types of instrument than those employing an
open pan, may also be multiplied by a constant throughout the
series, and this constant might be the area of the surface em-
ployed, or any other number that may be chosen. But it can-
not be too strongly emphasized that such treatment is to be
applied only to series of readings that are already comparable,
and that no constants can be found by which readings from
different types of instruments may be rendered comparable.
The use of depth units in comparing water losses from open
pans has introduced and supported a fallacy that is extremely
hard to combat in the minds of those who have not given the
subject of atmometry serious attention. This fallacy is based
upon the mistaken idea that the area of the evaporating sur-
face is the only surface characteristic that can influence the
rate of evaporation. If different sizes of pans are employed
the readings are incomparable, and they remain incompar-
able even after each one has been divided by the area of its
own water surface. Eeadings must be stated as from a cer-
tain instrument, in any event, and the application of an areal
coefficient only complicates matters. To avoid the continua-
tion of this fallacy, as much as may be, it is highly desirable
that all atmometric readings be stated in terms of weight or
volume, even though they were originally obtained by measure-
ments of depth.
The worst feature of the use of depth units in pan atmome-
try is that it has led to another fallacy, by which these depth
units are taken to be equivalent to the other depth units that
are employed in the measurement of rainfall. The two classes
of units look alike but they are widely different in their mean-
ings. An example may illustrate this very important point.
Suppose that the rainfall for a certain place is found to be
75 cm. (of depth) for a certain year, and suppose that the
observer states that the evaporation from a Weather Bureau
pan for the same period was 90 cm. (also of depth). In such
a case students of climatology have been led to say that evapo-
367] B. E. Livingston 169
ration exceeds precipitation by a certain depth, 15 cm. in this
example. But this means nothing at all ; if the pan used had
been larger or smaller, of different shape or material, or if a
wet soil surface had been employed, etc., the result would have
been quite different, and the climatic conditions would surely
not have been altered by merely changing the atmometer. On
the other hand, if any other form or size of raingage had been
employed the re-suits would be sensibly the same. The amount
of evaporation depends largely upon the atmometer but the
amount of rainfall recorded is practically independent of the
raingage, so long as the latter is a raingage at all. It is legiti-
mate to state the index of rainfall in depth units, for this is
not seriously influenced by the internal characteristics of the
gage, a statement that cannot be made of the index of evapo-
ration, nor even of the index of atmospheric evaporating pow-
er. The only logical way by which atmometric and precipita-
tion measurements may be compared is by means of their
ratio, in which case one set of measurements may be in depth
units and the other in volume or weight units. They are not
commensurable in any case, so it is best not to have them even
appear as though they were commensurable. Other considera-
tions, into which I cannot go in this place,, lead unequivocally
to the same conclusion.
Fortunately, there is no serious difficulty encountered in
the statement of the time feature of atmometric measure-
ments. For short periods the hour is most convenient, for
longer periods the day, week and year are all suitable. Since
months vary in length, monthly atmometric indices are un-
satisfactory. After the three features of the unit to be used
have been decided upon, it is necessary to remember that at-
mometric measurements, like other power measurements, al-
ways apply to a certain set of circumstances and to a certain
time period. The set of circumstances here emphasized is the
surroundings of the atmometer, they comprise the various
features of its exposure. The readings refer -to the evaporat-
ing power of the air only for the particular location in which
the instrument was operated. The evaporating power of the
170 Vapor Tension Deficit [368
air may be very different in two locations only a few centi-
meters apart. The differences here encountered are much
greater than the similar ones met with in thermometry and
the general exposure of the instrument needs to be stated in all
climatological studies of atmometry. The readings obtained
are taken as averages for the time period of operation and are
stated with reference to a shorter time unit.
To summarize the points brought out above, every atmo-
metric measurement should be formulated so as to include all
the five features indicated by letters in the following state-
ment, which is given as an illustration. The atmometric in-
dex for location A, for the period of operation E, is found to
be G units of water lost per time unit D from an atmometer
of type E. Filling in the features represented by these let-
ters, to render the illustration more concrete, we may say :
The atmometric index for a place 1 meter above the ground in
the center of a large field of clover in northern Ohio, for the
period of operation from May 1 to May 10, 1916, was found
to be 12 grams of water lost per day from a standard white
spherical atmometer. If any of these five features is omitted
from the statement, the meaning is rendered vague and un-
certain.
THE VAPOR TENSION DEFICIT AS AN INDEX OF THE
MOISTURE CONDITION OF THE AIR
By BURTON E. LIVINGSTON
Studies on the manner in which external conditions con-
trol the activities of animals and plants must deal with the
moisture conditions of the air in all cases where the organ-
isms considered are aerially exposed. While atmospheric
evaporating power (measured with reference to some standard
evaporating surface) furnishes an index of the air conditions
that influence the rate of water loss from aerially exposed
organisms, it is frequently desirable to analyze this complex
369] B. E. Livingston 171
condition into its two components, the moisture condition of
the air and the velocity of air movement or circulation. For
such an analysis atmometric observations are of course inade-
quate. Furthermore, it is often requisite to compare different
evaporating powers of the air when the air movement is
known to be constant, in which case the moisture condition
is the only variable to be taken into account. Finally, in the
artificial control of the air conditions of culture chambers,
the rooms of dwellings, etc., it is frequently possible to main-
tain air circulation without much fluctuation and then to con-
trol the evaporating power by controlling the moisture con-
dition. In such cases it becomes important that serious at-
tention be given to the moisture condition of the air and its
adequate measurement.
By moisture condition is here meant that factor in atmos-
pheric evaporating power that is independent of the rate of
air movement. It is thus an index of a condition determined
by the state .of saturation of the air (with aqueous vapor) and
by the air temperature. Humidity, as commonly measured,
does not involve temperature. To make these relations clearer,
it may be added that the index of atmospheric evaporating
power should be equal to the product of the index of the mois-
ture condition and the index of circulation : / — lm X Ic,
Of course it is here assumed that all measurements of con-
ditions have been properly weighted and brought into corre-
spondence, in deriving the indices. Otherwise a coefficient of
proportionality needs to be applied to each of the quantities.
In this equation, the value Im is the one with which this
discussion deals.
The tendency of water to evaporate into air lying next to
the water surface is measured by the maximum vapor pressure
possible with the prevailing conditions of the surface. If pure
water is considered the maximum value may be obtained for
any given temperature, from published physical tables. It
will be lower than these published values if the water is im-
pure, or if it is held by imbibing solids, etc. It is a gas pres-
172 Vapor Tension Deficit [370
sure, and is expressed in pressure units, as the height of a
mercury column, fractions of an atmosphere, etc. It may be
considered as equal to the pressure that drives the water vapor
out of the liquid surface, which may be termed the vaporiza-
tion pressure. The temperature of the liquid lying close to
the surface exerts a marked influence upon the magnitude of
this pressure.
This tendency for water to evaporate is opposed by another
tendency, that of the air 'to deposit liquid water on the evapo-
rating surface ; it is the tendency of water vapor to condense.
This is measured by the partial pressure of water vapor in the
air lying next to the evaporating surface, and it may have any
value between zero and the maximum vapor pressure of water
vapor for the given air temperature. It also is a gas pressure
and is measured in pressure units. The most satisfactory
method of measuring it is by means of the Eegnault dew-point
apparatus, through determining the temperature of the dew-
point, the partial pressure of water vapor in the air being equi-
valent to the maximum vapor pressure of liquid water at the
temperature of the dew-point of the air. Another less satis-
factory method of determining this partial pressure is by
means of the sling psychrometer, the readings being inter-
preted by physical tables published for this purpose. .This
actual partial pressure of water vapor in the air may be termed
the condensation pressure.
From this it follows that the difference between the vapori-
zation pressure and the condensation pressure must deter-
mine the value of that factor of atmospheric evaporating
power that is not determined by air circulation. This differ-
ence is the vapor pressure deficit, measured as a pressure; it
is the excess of vaporization pressure over condensation pres-
sure. For most purposes of approximation it may be sup-
posed that the temperature of the liquid surface and that of
the general air are the same, but this is not strictly true, and
the temperature value employed in deriving the vaporization
pressure ought really to be measured just within the liquid,
371] B. E. Livingston 173
if the evaporating power of the air for any particular surface
is to be studied. The condensation pressure should be deter-
mined for the general atmosphere of the space under con-
sideration. If air circulation were infinitely rapid, which
means, practically, if there is a high wind, this deficit value
should be a measure of the evaporating power for the particu-
lar location considered. Also, if two sets of conditions are to
be compared, in which the air circulation is the same, then
the two atmospheric evaporating powers 'should be propor-
tional to the corresponding vapor pressure deficits; for the
other factor is then common to both sets.
To illustrate the use of the vapor pressure deficit, let it be
supposed that there are two rooms in which the air circulation
is alike, and let it be required to estimate the relative values
of the evaporating powers corresponding to the two rooms.
The data involved and the results obtained are shown below,
together with the two relative humidity values, as usually
given in such comparisons.
Air tern- VAPOR PRESSURE Vapor pres- Relative
perature Maximum Actual sure deficit humidity
deg. c. mm. of Hg. mm. of Hg. mm. of Hg. per cent.
Room 1. 20° 17.41 14.50 2.91 83
Room 2. 25° 23.55 6.14 17.41 26
The values used in this example have been so chosen that the
deficit for Eoom 2 is 17.41 mm., just what it would be for
Room 1 if the actual vapor pressure were taken as zero. This
is the maximum deficit for a temperature of 20°. Neverthe-
less, it is seen that the actual vapor pressure for Room 2 is far
from zero. This emphasizes the point that the maximum
evaporating power of the air increases with the temperature,
air pressure, and circulation remaining the same.
Such comparisons have usually been made in terms of rela-
tive humidity, the values for which are presented in the last
column of the tabular arrangement just given. This mathe-
matical abstraction is the ratio of the actual to the maximum
174 Vapor Tension Deficit [372
vapor pressure of water vapor in the air, while the vapor pres-
sure deficit is the difference between these two vapor pressures.
Eelative humidity percentages are without value unless the
air temperature is also given, whereas the deficit values need
no reference to air temperature for their interpretation.1 The
fallacy in the employment of relative humidity clearly lies in
the fact that its values are ratios and that the denominator of
the ratio varies with air temperature; different percentage
values cannot .be comparable unless they are calculated to the
same base.
In the illustration given above, the relative humidity index
for room 1 is 3.25 times as great as that for room 2, and the
popular conception of relative humidity might lead to the
erroneous supposition that the evaporating power of the air
for room 2 should be 3.25 times as great as that for room 1,
whereas this last number should be the value of the fraction
!M! or 5.98.
2.91
The real uselessness of the concept of relative humidity and
the manner in which this concept is frequently misleading
are brought out by the fact that the index of relative humidity
may be identical for two rooms or for two climatic stations,
and (owing to a difference in air temperature) the mois-
ture factor of the evaporating power of the air may be very
different in the two cases. Thus, a relative humidity of 60
per cent, corresponds to an air moisture factor of 10.44 mm.
at 20°, and to one of 14.13 mm. at 25°. The moisture con-
dition of the air in the second case is much higher, but the
relative humidity values fail to suggest any difference.
One of the most serious reasons for discontinuing the use
of relative humidity lies in the fact that the moisture con-
dition of the air generally varies from hour to hour and from
1 For some very true remarks in this connection, see : Stevens, Neil
E., " A method for studying the humidity relations of fungi in culture.'1
Phytopathology 6: 428-432. 1916. Other references are there given.
373] B. E. Livingston 175
day to day, for the same place, which makes it necessary in
climatic discussions to resort to averages and means. While
the index of relative humidity for any instant may be readily
interpreted by use of the corresponding air temperature., there
is no possible way by which an average of several such indices
may be so interpreted ; the average temperature for the period
is of no use for this purpose, since the march of temperature
for the period is not necessarily at all related to that of the
moisture condition. The only way to give definite meaning
to a relative humidity mean is to obtain the original humidity
values from which the mean was derived (together with the
corresponding air temperatures), to substitute for each indi-
vidual value the corresponding vapor pressure deficit, and to
derive the mean of the deficits, thus discarding relative hu-
midity altogether.
For biological experimentation, for hygienic studies of the
air moisture condition in dwellings, and for general climato-
logical purposes, it is very obvious that the whole concept of
relative humidity is hopelessly misleading; the sooner this
concept can be forgotten the more rapidly will knowledge ad-
vance. When it is not desirable or expedient to employ the
index of atmospheric evaporating power itself (as determined
directly by some form of atmometer), the moisture condition
of the air should be stated in terms of the vapor pressure de-
ficit, which demands no correction for air temperature and
may represent evaporating power in all comparisons where the
index of effective air circulation may be considered as constant.
176 ' Drying and Wilting of Plants [374
INCIPIENT DRYING AND TEMPORARY AND PERMANENT
WILTING OF PLANTS, AS RELATED TO EXTERNAL
AND INTERNAL CONDITIONS
By BURTON E. LIVINGSTON
It has been shown by Renner,1 by Livingston and Brown,2
by Lloyd 3 and by Edith B. Shreve,4 that the water content
of plant leaves, twigs, etc., is markedly lower after a period
of relatively great transpiration (as in the middle of the
day) than it is after a period of very small transpiration (as
in the latter part of the night). The moisture content of
leaves, for instance, was found (Livingston and Brown) to
exhibit a diurnal march, the rate of water loss from these
organs during the forenoon hours (or even during the 'whole
period of sunshine) being greater than their rate of water
intake, while the rate of foliar intake of water during the
night hours was greater than the rate of water loss. " The phe-
nomenon indicated by diminished water content in the day-
time was called incipient drying by Livingston and Brown.
Renner employed the term sdtigungsdefizit to denote the
similar phenomenon encountered in his experiments. The
experimentation of all but Renner, of the authors mentioned
1 Renner, 0., " Experimentelle Beitrage zur Kenntnis der Wasser-
bewegung." Flora 103: 171-247. 1911. Idem., " Versuche zur Me-
chanik der Wasserversorgung. I. Der Druck in den Leitungsbahnen
von Freilandpflanzen. Ber. Deutsch. Bot. Ges. 30: 576-580. 1912.
2 Livingston, B. E., and Brown, W. H., " Relation of the daily
march of transpiration to variations in the water content of foliage
leaves." Bot. Gas;. 53: 309-330. 1912.
3 Lloyd, F. E., " The relation of transpiration and stomatal move-
ments to the water content of the leaves of Fonquieria splendens."
Plant World 15: 1-14. 1912. Idem., "Leaf water and stomatal
movement in Gossypium, and a method of direct visual observation
of stomata in situ. Bull. Torrey Bot. Club 40: 1-26. 1913.
4 Shreve, Edith B., " The daily march of transpiration in a desert
perennial." Carnegie Inst. Wash. Pub. 194: Washington, 1914.
375] B. E. Livingston 177
above, was carried out in an arid region, with high transpira-
tion rates, but the results of Renner were obtained in a very
moist summer in Munich, so that it appears to be fairly well
established that this phenomenon is general in plants. Of
course, incipient drying is more pronounced with high atmos-
pheric evaporating power and intense sunshine than with
aerial surroundings of less aridity, and it is less pronounced
in plants with low transpiring power than it is in less xero-
philous forms.
From Eenner's experiments, and also from those of Living-
ston and Hawkins,5 it appears that the rate of absorption of
water by plant roots is determined by two conditions, which
may be called, respectively, the absorbing power of the roots
(internal) and the supplying power of the soil, or other
medium in which the roots lie (external). It also appears
that the internal one of these conditions (absorbing power of
the roots) is at least partly controlled by the degree of incipi-
ent drying occurring in the plant, which, in turn is partly
dependent upon the rate of transpiration. Other conditions
being unchanged, the plant takes up more water from the
soil when the transpiration rate is high than when it is
lower. If incipient drying becomes sufficiently pronounced
its presence is made evident, first by loss of turgor in the
plant, then by temporary wilting6 (from which the wilted
tissues may recover when transpiration is subsequently de-
creased), then by permanent wilting7 (from which the plants
5 Livingston, B. E., and Hawkins, Lon A., "The water relation
between plant and soil." Carnegie Inst. W\ash. Pub. 204: 5-48.
Washington, 1915.
6 Brown, W. H., " The relation of evaporation to the water content
of the soil at the time of wilting." Plant World 15: 121-134. 1912.
7Briggs, L. J., and Shantz, H. L., "The wilting coefficient for
different plants and its indirect determination. U. S. Dept". Agric.
Bur. Plant Ind. Bull. 230: 1912. Caldwell, J. S., "The relation of
environmental conditions to the phenomenon of permanent wilting in
plants. Physiol. Res. 1 : 1-56. 1913. Shive, J. W., and Living-
ston, B. E., " The relation of atmospheric evaporating power to
soil moisture content at permanent wilting in plants. Plant World
17: 81-121. 1914. .
178 Drying and Wilting of Plants [376
cannot recover without special treatment), and finally by
death and actual desiccation.
Incipient drying of leaves, whether they show any signs
of wilting or not, may be said to be due to inadequate water
supply to these organs; no matter how great might be the
rate of foliar water loss, the transpiring cells should not suf-
fer any diminution in their water content if the rate of
entrance of water into these cells were only sufficiently great.
The question therefore arises, as was mentioned by Living-
ston and Hawkins, to what extent is this inadequacy in the
rate of foliar water supply to be considered as due to inade-
quate water supplying power, of the soil, and to what extent
may it be due to inadequate absorbing power of the roots and
inadequate conducting power of the stems, petioles, etc. ? In
wilting leaves, for example, is the insufficient rate of water
supply due to an external condition in the soil or to an inter-
nal condition, within the plant body?
This is a very important question, both with regard to the
general problem of plant water relations and with respect to
the practical problem of drought resistance in plants. A
quantitative answer for plants growing in the open is of
course impossible at present, but some light has been thrown
upon the consideration of this question by some experiments
recently carried out in the Laboratory of Plant Physiology.8
The matter in hand was approached by making the water-
supplying power of the root surroundings very great ; the test
plants were grown in water-culture instead of in soil, so that
the external resistance offered to water absorption by the root
surfaces may be considered as practically nil and therefore
constant. Under such conditions the actual rate of water
absorption must be very nearly proportional to the absorbing
power^of the root system.
Two methods were employed, for both of which the tran-
spirational rates were determined by weighing, in the ordi-
8 Mr. E. S. Johnston carried out the manipulations in these
experiments.
377] B. E. Livingston 179
nary way. By one method the absorption rates were deter-
mined as volumes, the plant being sealed into a bottle com-
pletely filled with the nutrient solution arid furnished with a
burette for measuring the volume of water absorbed. Tem-
perature changes were corrected for by means of readings
taken from a similar arrangement of bottle and burette with-
out any plant. By the other method arrangement was made
by which the plant could be suspended from the balance arm,
its roots in the culture solution, with the surface of the latter
always at the same mark on the basal part of the stem when
the balance was in equilibrium. Thus, the buoyancy tending
to lift the plant was very nearly the same at all weighings.
During this weighing the split cork otherwise closing the cul-
ture jar was removed. Observations were obtained usually
at hour intervals, from before daylight in the morning to late
in the evening. The plants used were : Coleus blumei, Fago-
pyrum esculentum (buckwheat) and Mimosa pudica (sensi-
tive plant). The experiments were carried out in an experi-
ment greenhouse, in the autumn and early winter. The
nutrient solution employed was of the Shive 3-salt type,
apparently physiologically balanced as to salt proportions,
and its total osmotic concentration was about 1.75 atmos-
pheres. The results of eight tests, at different times of the
year, may be briefly stated as follows.
(1) Sept. 20, clear sky. Buckwheat plant. Transpiration was
greater than absorption for the period 8:50 a. m. to 1:50 p. m.,
incipient drying amounting to 0.63 g. Absorption was greater than
transpiration for the period 1:50 to 5:50 p. m., the plant gaming in
weight 0.15 g. Wilting began during hour ending 10:50 a. m., when
incipient drying amounted to 0.27 g. Transpiration for this hour
was 0.81 g. and absorption was 0.59 g. Transpiration for last hour of
incipient drying was 0.98 g. and absorption was 0.96 g. Five out of
six leaves were permanently wilted and never recovered.
(2) Sept. 21, clear sky. Buckwheat plant. Transpiration was
greater than absorption for the period 9:20 a. m. to 1:20 p. m.,
incipient drying amounting to 0.24 g. Absorption was greater than
transpiration for the period 1:20 to 9:20 p. m., the plant gaining
in weight 0.38 g. Wilting began during hour ending 10:20 a. m.,
when incipient drying amounted to 0.08 g. For this hour transpira-
180 Drying and Wilting of Plants [378
tion was 1.36 g. and absorption was 1.28 g. Transpiration for the
last hour of incipient drying was 1.26 g. and absorption was 1.18 g.
No permanent wilting occurred.
(3) Sept. 23, cloudy or partly cloudy. Buckwheat plant. Ab-
sorption was greater than transpiration for the period 6:50 to 7:20
a. m., the plant gaining 0.03 g. Transpiration and absorption were
equal (0.08 g.) for the period 7:20 to 7:50 a. m. Transpiration was
greater than absorption for the period 7:50 a. m. to 2:20 p. m., incipi-
ent drying amounting to 0.59 g. Wilting began during hour ending
10.20, when incipient drying amounted to 0.33 g. Transpiration
for this hour was 0.56 g. and absorption was 0.44 g. Transpiration
and absorption for the period of incipient drying (7.50 to 9.20 a.m.)
were 0.67 and 0.46 g.; for the last period of incipient drying (12.30
to 2.20 p.m.) they were 1.49 and 1.43 g., respectively. Three out
of five leaves were permanently wilted and never recovered.
(4) Nov. 3, clear sky. Dark red Coleus plant. Transpiration and
absorption were equal (0.29 g.) for the hour 7:30 to 8:30 a. m.
Transpiration was greater for the period 8:30 to 11:30 a. m., incipi-
ent drying amounting to 0.35 g. Absorption was greater for the
period 11:30 a. m. to 7:30 p. m., the plant gaining in weight 0.68 g.
Transpiration and absorption were equal (0.16 g.) for the period
7:30 to 9:30 p. m. No wilting was noted. The evaporating power
of the air was 1.02 cc. (per hour, from the Livingston standard
white spherical atmometer) for the first hour of incipient drying.
Transpiration for this hour was 0.76 g. and absorption was 0.70 g.
(5) Nov. 4, cloudy. Dark red Coleus plant. Transpiration and
absorption were equal (0.11 g.) for the period 5:30 to 7:30 a. m.
Transpiration was greater for the period 7:30 a. m. to 2:30 p. m.,
incipient drying amounting to 0.47 g. Absorption was greater for
the period 2:30 to 5:30 p. m., the plant gaining in weight 0.10 g.
No wilting was noted. The atmometric index for first hour of
incipient drying was 0.33 cc. Transpiration for this hour was 0.10
g. and absorption was 0.01 g.
(6) Nov. 16, clear sky. Two buckwheat plants bound together
at base. Transpiration was greater than absorption for the period
9:30 to 11:30 a. m., incipient drying amounting to 0.17 g. Absorp-
tion was greater for the period 11:30 a. m. to 10:30 p. m., the plants
gaining in weight 0.33 g. No wilting was noted. Atmometric index
for last hour of incipient drying was 0.9 cc. Transpiration for this
hour was 1.83 g. and absorption was 1.79 g.
(7) Nov. 16, clear sky. Dark red Coleus plant. Transpiration
was greater than absorption for the period 9:45 a. m. to 3:45 p. m.,
incipient drying amounting to 0.89 g. Absorption was greater than
transpiration for the period 3:45 to 7:45 p. m., the plant gaining
in weight 0.78 g. No wilting was noted. The atmometric index
379] B. E. Livingston 181
for last hour of incipient drying was 1.3 cc. Transpiration for this
hour was 0.38 g., and absorption was 0.11 cc.
(8) Dec. 1, cloudy. Mimosa plant. Transpiration was greater
than absorption for the period 7:55 a. m. to 3:55 p. m., incipient
drying amounting to 2.97 g. Absorption was greater than tran-
spiration for the period 3:55 to 5:55 p. m., the plant gaming in
weight 0.27 g. No wilting was noted; the leaves were in night
position at end of last hour. Atmometric index for last hour of
incipient drying was 0.7 cc. Transpiration for this hour was 1.03 g.
and absorption was 0.87 cc.
These data show very clearly that incipient drying, tempo-
rary wilting, and even permanent wilting of most of the
leaves, may occur without any resistance at all to water-
absorption by roots. These phenomena are here quite inde-
pendent of such resistance to water intake as may be offered
by unsaturated soils. Furthermore, in the complete absence
of environmental resistance to water absorption by the root
system, incipient drying may begin with an evaporating
power of the air as low as 0.33 cc. per hour from the Living-
ston standard white sphere (Coleus, Nov. 4). Consequently,
it does not require a high atmometric index to render the
transpiration rate larger than the rate of absorption, in the
case of some plants at least. The truth of this statement must
be much more pronounced when the plant roots are sur-
rounded by ordinary, fairly dry soils, which interpose an ex-
ternal resistance to water intake.
Unfortunately, atmometric observations were omitted in
the first three tests, so that it is not possible to state what
order of atmometric index values produced the wilting phe-
nomena recorded for Sept. 20, 21 and 23. It is, of course,
certain that these index values were not exceptionally high,
however; the index for Baltimore is never high, and there
\vas no artificial heat applied to the greenhouse on these
days, so that the index value was not artificially raised. It
is worth something to note that permanent wilting of most
of the leaves of healthy buckwheat plants occurred in an
unheated greenhouse in Baltimore on Sept. 20, with clear sky,
and on Sept. 23, with partly cloudy sky.
182 Deficient Soil Oxygen [380
Obviously, the absorbing powers of these plants were inade-
quate to supply water as rapidly as it was lost by transpira-
tion during the hours when this loss was most rapid; the
inadequacy was within the plant, an internal condition. It
is suggested that the power of stem and petioles to conduct
water from roots to leaves is here also inadequate, but on
this point further experimentation will be required.
One definite advance in our knowledge of the water rela-
tions of plants is made by the data here considered; it may
now be clearly stated that none of these three stages or de-
grees of incipient drying need necessarily be related to soil-,
moisture conditions at all. That they may sometimes be so
related, when the soil about the root system fails to supply
moisture to the root surfaces as rapidly as these are able
to absorb it, is sufficiently clear on a priori grounds.
THE EFFECT OF DEFICIENT SOIL OXYGEN ON THE
ROOTS OF HIGHER PLANTS
By B. E. LIVINGSTON AND E. E. FREE
During the last three years experiments have been in
progress in the Laboratory of Plant Physiology on the oxy-
gen requirement of the root systems of higher plants. A
technique has been devised by which the root system, con-
tained in normal soil, can be sealed off from the air and th-
soil atmosphere controlled in composition as may be desirecL
The aerial portions of the plants project into the atmosphere
of the greenhouse. Water is supplied to the roots by means
of the Livingston auto-irrigator.1 It has been found that
1 Livingston, B. E., " A method for controlling plant moisture."
Plant World 1 1 : 39-40. 1908. Hawkins, Lon A., " The porous clay
cup for the automatic watering of plants." Plant World 13: 220-227.
1910. Livingston, B. E., and Hawkins, Lon A., "The water-relation
between plant and soil." Carnegie Inst. Wash. Pub. 204: 5-48. 1915.
381] B. E. Livingston and E. E. Free 183
the response of the root-system to deficiency of oxygen in
the soil atmosphere varies widely in different kinds of plants.
Some species are injured by a very slight deficiency below
the oxygen content of the general atmosphere. A swamp
willow, probably Salix nigra, endures successfully the com-
plete, or almost complete, exclusion of oxygen from its roots.
In the case of those plants which are injured by deficient
soil oxygen it is interesting physiologically that the first
effect of oxygen deprivation is an interference with the ab-
sorption of water by the roots. In the experiments the
apparatus for the supply of water is so arranged that the
amount of water taken up by the soil from the porous cups
of the auto-irrigator can be measured for periods as short
as one hour. The amount of water thus taken up depends
in part on the temperature. The surface tension of the
water films in the soil varies with temperature and this con-
trols the amount of water held in the water-film system.
However, this error disappears for periods the initial and
final temperatures of which are nearly the same (for in-
stance, the usual 24-hour period) and a correction can be
made for the error in the case of shorter periods or other
periods which do not satisfy this condition. When the tem-
perature error is thus eliminated, the absorption of water
from the auto-irrigator is closely parallel to the intake of
water by the plant roots. With the plants that are sensi-
tive to deficiency of oxygen in the soil air, it is found that
the replacement of the normal soil atmosphere by nitrogen
is followed within a few hours by nearly complete cessation
of water-intake by the roots. With the most sensitive species
tested, namely, Coleus blumei and ffeliotropium peruvianum,
this cessation of water-intake occurs always within 24 hours,
usually within 12 hours, after the soil oxygen is removed.
This time period varies with the individual plant, perhaps
because of differences in the root-system but probably also
because of differences in the completeness with which the
soil oxygen originally present is replaced by the nitrogen.
Since the oxygen must be displaced by washing out with
184 Deficient Soil Oxygen [382
the nitrogen it is impossible to be sure that the replacement
is ever absolutely complete at the beginning of the experi-
ment.
The cessation of water intake, as shown by the stoppage
^of absorption from the auto-irrigator, is always the first
sign of injury. With Coleus and Heliotr opium it is followed
in from one to six days by progressively lessened turgor of
the shoot and leaves and finally by wilting and death. With
Coleus, the admission of oxygen to the soil before death has
actually occurred is followed by the slow recovery of the
plant. Heliotropium does not so recover, even if oxygen is
re-supplied before the wilting has become extensive or
severe. With Nerium oleander, which does not wilt, the
symptom of injury which follows next after the cessation
of water intake by the roots is the yellowing and loss of
leaves.
On removal and examination of the injured plants the
root systems are found to be dead and the roots partly dis-
integrated. When the injury has been slight or recent, in-
dividual roots are determinately dead only in parts of their
length, regions of brown discoloration alternating with re-
gions of apparently healthy root. When Coleus is first in-
jured and then revived by re-admission of oxygen it forms
a new root system, the new healthy roots being clearly dis-
tinguishable from the older dead ones. These new roots start
always from the base of the stem, as in a rooted cutting.
They have never been observed to start from any portion
of the older root system. If one begins with a Coleus plant
which has a small root system, or with an unrooted cutting,
or with a previously injured plant which will form new
roots, it is possible to grow such a plant with a soil atmos-
phere somewhat below normal in oxygen content. In this
case the shoot does not attain so large a size as the shoot
of a normal control plant and is more susceptible to injury
by drouth, as, for instance, by increase in the evaporating
power of the air. The root system of such a plant, grown
with deficient oxygen, is less developed than that of a normal
383] B. E. Livingston and E. E. Free 185
plant and the roots are long, thin and little branched, and
range widely through the soil.
When Coleus plants of different sizes are deprived of soil
oxygen, the cessation of water intake and the subsequent
symptoms of injury appear first and are most severe on
the plants which have the larger root systems. Again, a
plant with a small root system will tolerate a lesser oxygen
content in the soil than will a plant with a large root system.
This implies that the crucial matter is the supply of oxygen
per unit of root surface (or volume) and this is confirmed
by the fact that a low oxygen content in a frequently changed
atmosphere is less injurious than a higher oxygen content
with less frequent changes.
The evidence suggests that the cause of injury by exclu-
sion of oxygen from the roots is an interference with the
respiration of the protoplasm of the root cells, resulting in
the death of this protoplasm and the consequent failure
of the roots to function as water absorbers for the plant.
There is no reason, however, to assume any "vital" func-
tion of the root protoplasm in promoting water absorption.
The protoplasmic coagulation which is, or accompanies,
what is called death would constitute in itself a sufficient
change to explain, on a purely physical basis, this effect on
water absorption. The fact that the roots of at 'least one
plant (Salix) appear to function normally in the absence
of free oxygen raises the interesting question whether the
respiration of these roots may not be anaerobic. It is im-
ppssible to answer this question finally. There is a theoret-
ical possibility, in our experiments, of some small access of
free oxygen from some source not now suspected. However,
the sharp difference in the behavior of Salix and of Coleus
under identical treatments suggests some important differ-
ence in the respiratory habits of the roots of the two species.
186 Soil-Moisture Minimum [384
THE EXPERIMENTAL DETERMINATION OF A DYNAMIC
SOIL-MOISTURE MINIMUM
By HOWARD E. PULLING
The conditions determining the rates of water movement
in soils have long been recognized as of great importance
in plant physiology, since they not only limit the amount
of water a given root system may receive but also modify
the effects of all soil processes upon rooted plants. In aerated
soils water is moved by surface forces of the soil-moisture
films. The magnitude of these forces is dependent upon the
curvature of the film-air surfaces and not upon the amount
of water in the soil, so that a soil volume might augment
its water content at the expense of another contiguous soil
volume that contained actually less water than the first.
The amount of water that may be moved in unit time de-
pends, however, also upon the amount of water in the films
and a certain minimum should exist below which the quan-
tity of water subject to capillary movement is too small to
admit of any but negligible rates, regardless of the mag-
nitude of the surface forces.
In aerated soils the water that responds to surface tension
urge is accumulated around the points of contact of soil
grains, so that the water adsorbed upon the surface of the
grains, imbibed by the soil colloids and held as water of
hydration by the grain constituents need not be considered
in the present discussion. It is apparent that the greater
the number of such points of contact between the soil grains
in a given gross volume of soil, the greater should be the
number of similar capillary masses of water and, conse-
quently, the greater should be the amount of water in the
soil when the rate of capillary movement becomes negligible.
Accordingly a complete statement of this minimum for any
soil may be represented not by a point but by a curve, in
385] H. E. Pulling 1ST
which the conditions of the soil-air-water system are repre-
sented in terms of any two of the three components.
For convenience the components soil grains and water may
be selected. The number of points of contact in any gross
volume are determined by the number, size, shape and ar-
rangement of the soil grains. In a sufficiently large volume
(a few cubic centimeters, for arable soils) the soil grains
may be considered as possessing an average density, size
and shape, and this average will not change when other
samples of the same soil are considered. Likewise if two
samples of the same volume have the same number of soil
grains, possessing the same average characteristics, it may
be assumed that the average arrangement of grains is the
same in each. This will be the more strictly true the longer
the grains have existed in those volumes, since the forces
of surface tension and gravity will tend to place them in
the most stable positions. A relative measure of the proper-
ties of a mass of soil grains may thus be obtained for any
one soil in terms of its dry weight per unit of gross volume,
termed the packing.
The properties of the water masses in the soil may also be
considered as being of average character and since these prop-
erties depend upon the shape and size of the water masses,
which in turn depend upon the shape and size of the spaces
about the points of contact of the soil grains, the number
of these points and the amount of water in the soil, they
will be sufficiently defined by the amount of water and the
amount of soil contained in each unit of gross volume. When
these amounts are determined for samples of any given soil,
each uniformly packed and permitting only a negligible rate
of water movement, the data are at hand for plotting the
experimental approximation to the minimum moisture curve
between the limits of packing encountered in the samples.
A method has been devised by the use of which samples
of any given soil, each of approximately uniform packing,
may be obtained with water contents so small that the rate
of water movement is about 0.001 gram in 24 hours through
188 Sub-Artie Soil [386
an area of 30 square millimeters. If the water contents per
unit of gross volume of a number of such samples of the
same soil are plotted as ordinates, and the corresponding dry
weights are plotted as abscissas, the graph obtained by con-
necting the points is the positive portion of an approximately
paraboliform curve that is symmetrical about the horizontal
axis. This graph ascends steeply in the region of light pack-
ings, indicating the relatively large effect of adding more
soil to a volume of low soil content. Its tendency to become
horizontal indicates that, with dense packings, the addition
of more soil but slightly increases the water content at the
dynamic minimum.
The amount of water that exists in a given soil at a given
packing above the minimum point for that packing is sub-
ject to capillary movement, so that the determination of the
minimum is of great value in calculating the maximum rate
at which water may move through the given soil under those
conditions. Because the graphs vary in height and slope,
at corresponding points, from one soil to another they should
also serve as soil characteristics by which various soils might
be recognized.
SOME UNUSUAL FEATURES OF A SUB-ARCTIC SOIL
By HOWARD E. PULLING
A preliminary survey of the ecological features of some
sub-arctic forests during the past summer yielded informa-
tion concerning the soils that emphasizes the need of in-
cluding the physical root -environment in an ecological study
of such regions. The chief soil over the major portion of
the area visited1 was a gray to buff colored lacustrine clay
1The valleys of the Nelson river and its tributaries near Split
Lake, which is situated in northern Manitoba, Canada, at about 56 o
north latitude and 96° west longitude.
387] H. E. Pulling 189
formed from rock flour in the bed of ancient lake Aggasiz.
The upper limit of frozen soil encountered during the sum-
mer varied from a depth of a few inches, near the water's
edge on a shore with a north exposure, to about six feet on
a slope well above the water line and with a southeast ex-
posure. It is highly probable that one of the most effective
agencies conditioning local distribution of plant species is
the depth at which frozen soil is encountered. Large trees
and other deeply rooted plants could not exist in soils made
too shallow by the presence of perpetually frozen soil near
the surface.
The soil of the spruce forest, which is the characteristic
type of this region, is covered chiefly by sphagnum, often to
a depth of several feet. Large amounts of water are held
by the moss so that these forests resemble those of temperate
regions at the borders of swamps and marshes. If the forest
is situated on a hillside, however, the soil underneath the
moss is usually dry and if exposed in windy weather will
blow as dust. This may perhaps be explained in the light
of knowledge of the conditions above and below the dry
layer. This dry stratum rests upon frozen soil, which be-
cause of its lower vapor pressure and of other probably less
effective properties, should continually absorb water from
the adjacent, unfrozen soil. Thus, making-the easily justified
assumption that the soil was originally wet, the conditions
exist for almost completely drying it, provided it should not
regain the water lost. The light snowfall in this region
would be unlikely to produce large amounts of water in the
spring, especially on these slopes where drainage in the spring
is rapid over the frozen surface of the soil, the relatively
small amount remaining being conceivably retained by the
highly absorbent sphagnum covering. The summer rains,
which, although frequent, bring comparatively little water,
are apparently no more than sufficient to supply the trans-
piration loss of the plants exposed to almost continuous winds
and often to bright sunshine for many hours a day.
Eoots penetrate this dry layer only to a slight extent,
190 Melanose and Stem-End Rot [388
although organic deposits occur down to the frost line.
These deposits are lamelliform, and each appears to be con-
tinuous from its lowest point to the surface of the soil.
Whether they originated from the decay of roots that had
penetrated this layer while it contained more water than it
does now., or whether they were formed by slow seepage
from the surface, cannot be decided from the information at
hand. The occurrence of small landslides in which dry soil
was found above and below the layer in which the slipping
occurred, indicates., however, that water may move in a thin
sheet of soil and either form these deposits by carrying or-
ganic matter from the surface, or, finding them ready formed,
traverse them to the deeper portions. Since these layers are
rich in organic matter it is probable that their constituents
would cohere when frozen, which is not true of the dryer
soil about them. This may perhaps account for the state-
ments often made that in the winter or spring, frozen soil
may be encountered at the surface and also below it, in
sheets, at intervals.
Whether due to this drying and being frozen in the dry
condition, or to other more obscure causes, the soil of this
dry layer is often flocculated to such a degree that it resem-
bles a mass of small clay pellets. Even after wetting this
flocculated soil retains its spherulate character.
THE GEOGRAPHICAL DISTRIBUTION OF THE CITRUS
DISEASES, MELANOSE AND STEM-END ROT
By H. S. FAWCETT
A general survey of the citrus districts of the United
States and Cuba has shown that the distribution-areas of
some of the important fungus diseases are not coextensive
with the areas where the host is cultivated. This fact is
strikingly brought out by an examination of the distribu-
tion of some of the diseases that have been present in these
regions for a long time.
389] H. 8. Fawcett 191
An interesting example of an old, well-known disease with
a rather limited distribution is melanose, which is due to
Phomopsis citri. The fungus produces small, brown pus-
tules on the surface of rapidly growing leaves, twigs and
fruit. It was discovered in 1892 and was first definitely
described, by Webber, in 1897. At that time melanose was
already a rather serious disease in the middle portion of the
peninsula of Florida. During the past 20 years, citrus
nursery stock has been freely interchanged between different
parts of Florida, and thousands of acres in Cuba have been
brought into citrus culture for the first time, the stock for
planting being derived from Florida, and yet the area over
which the disease is now of serious commercial importance
is confined roughly between the parallels of 27%° and
291/2° N. latitude in Florida.
Southward from this area melanose gradually becomes
less and less severe and it finally disappears entirely, so that
the southernmost citrus districts of the state are free from
it. In Cuba, if the disease occurs at all, it is of no commer-
cial importance; I was unable to find any evidence of it in
the island in January, 1914. North of the Florida area of
most serious injury, melanose occurs in a less severe form,
and a mild form of the same disease has been reported for
southern Alabama and Louisiana, but it is apparently not
serious in these regions. No trace of this disease has ever
been found in California.
The same Phomopsis that produces melanose also plays a
part in the so-called stem-end rot of mature or nearly mature
citrus fruits, and it is an interesting fact that this fruit rot
has never been known to be serious outside of the areas
where melanose is also of commercial importance. Like
melanose, stem-end rot has not been reported as occurring
either in Cuba or in California.
The reasons for the peculiar distribution of Phomopsis
citri, as above described, are not at all understood, and we
cannot regard our knowledge of melanose and stem-end rot
as at all nearly complete until a properly substantiated ex-
192 Melanose and Stem-End Eot [390
planation of these geographical limitations may be found.
Such problems as this are worthy of serious attention. Some
of the logical possibilities of this particular case may be
mentioned, by way of preparing for further observations and
for constructive experimentation.
One possibility that always presents itself in connection
with a limited geographical distribution of any parasite is
that sufficient opportunity or time may not yet have been
afforded for the parasite to become distributed throughout
the area occupied by the host. But this possibility seems not
to apply in the present case. As has been mentioned, after
melanose had become common in central peninsular Florida
there took place a free interchange of many kinds of citrus
nursery stock between Florida, on the one hand, and Cali-
fornia and Cuba, on the other. Many carloads of young
citrus trees were shipped from nurseries located in the
Florida area where this Phomopsis was most virulent, no
effective quarantine regulations were in operation at that
time, and it is impossible that the fungus has not long since
been thoroughly distributed. All or nearly all of the citrus
varieties grown in Florida have been planted, at one time
or another, in California, and the recent and extensive
Cuban plantings have been made with nursery stock from
Florida.
Of course, climatic conditions may furnish an explanation
of the facts here dealt with, but the climatic relations of a
fungus like Phomopsis citri are probably even more complex
than are those of higher plants. For the growth of such a
parasite it is not only necessary that the climatic conditions be
suitable for this organism, but it is also essential that the com-
plex of these conditions be naturally so arranged or balanced
that the host-plant may be in just the proper state to favor
the virulent development of the parasite. The time factor
is especially important in the process of infection; it must
happen that the host is in a condition to be readily infected
just at the time when the fungus spores reach it.
391] H. 8. Fawcett 193
One of the necessary conditions -for the occurrence of
melanose, when Phomopsis is present, appears to be a con-
siderable degree of air humidity, at the season of most rapid
growth of new shoots and of the fruit, and the absence of
the disease in California may possibly be accounted for by
the dryness of the air at the time when the trees are most
susceptible to infection. This, however, does not seem to
be a sufficient reason for the absence of melanose in the
southernmost parts of Florida and Cuba.
Edgerton has recently emphasized the apparent bearing
of temperature conditions on the occurrence of certain plant
diseases in sub-tropical climates. He is convinced that the
absence of anthracnose in beans grown at certain seasons in
Louisiana is due to the fact that the average temperatures
for those seasons are above the optimum for the growth of
the pathogenic fungus. If this is true in the case of anthrac-
nose it may also be true in the case of melanose. The first
requirement for a test of this suggestion is, of course, some
definite knowledge concerning the temperature relations of
Phomopsis itself, and experimentation is now in progress
in this direction.
PRELIMINARY NOTE ON THE RELATION OF TEMPE-
RATURE TO THE GROWTH OF CERTAIN
PARASITIC FUNGI IN CULTURES
By H. S. FAWCETT
Interest in the temperature relations of plant growth is
rapidly increasing, and, as improved methods become avail-
able, increasingly precise studies are being made of the in-
fluence of temperature upon growth as variously measured.
The study upon which the writer is at present engaged aims
to compare the temperature-growth curves for cultures of
a number of fungi that produce diseases of citrus trees and
that are confined to limited geographical areas. It is hoped
13
194 Temperature and Growth of Fungi [392
that the results obtained may be of value, not only in inter-
preting the geographical distribution and seasonal occurrence
of these diseases, but in suggesting further means for their
control.
A suitable solid medium in petri dishes is employed, a
transfer (of spores or a small piece of mycelium) being
made to the center of each culture dish, and the resulting
growth is measured in terms of the 24-hourly increase in
the mean diameter or radius of the nearly circular area
occupied by the fungus. Various precautions are taken to
have all conditions, excepting that of temperature, as nearly
alike as possible throughout the entire investigation.
The preliminary work so far carried out has been con-
fined largely to Pythiacystis citrophthora, which attacks both
the trunk and fruit of the lemon tree. To illustrate the
kind of results obtained, at the temperatures 10°, 20°, 28°
and 33 °C. the radial, 24-hourly growth-rates of this fungus
were 2.5, 6, 7.5 and 2.6mm., respectively. For a rise of
temperature from 10° to 20° the growth rate was thus
somewhat more than doubled, from 20° to 28° it increased
25 per cent., and at 33° the rate was nearly the same as
at 10°. This kind of a relation between the growth-rate and
temperature was of course to be expected, and interest in
this research will lie largely in the differences between the
temperature-growth curves of the different fungi, especially
in the differences between their optimum temperatures for
growth.
Although bacteria and fungi, as studied by other work-
ers, appear to exhibit gradually diminished growth-rates
when temperature and the other environmental conditions
are maintained unchanged for a long time, yet no such slow-
ing down of growth has been encountered with this Pythia-
cystis; for example, the same growth-rate has been observed
to continue unchanged for a period of eight days or more.
393] E. E. Free 195
SYMPTOMS OF POISONING BY CERTAIN ELEMENTS,
IN PELARGONIUM AND OTHER PLANTS
By E. E. FKEE
In connection with other experiments on the effects of pois-
onous elements on plants, qualitative tests have been made
of the symptoms of poisoning exhibited by the common cul-
tivated geranium (Pelargonium zonale) and by several other
plants, under the action of certain poisonous elements. The
plants were grown in soil under ordinary greenhouse condi-
tions. The poisons were applied by pouring the proper solu-
tions on the soil when the latter was sufficiently dry to
absorb and retain all of the added solution. Seven elements
were applied to Pelargonium in five concentrations each.
These were the following. Concentrations are in parts of the
poisonous element per million parts of soil by weight.
Concentrations
p. p. m.
Arsenic, as trioxide (As203) 2 to 500
Boron, as borax (Na^BA) 2 to 500
Copper, as sulphate (CuS04) 4 to 1000
Iron, as ferrous sulphate ( FeS04 ) 20 to 5000
Lead, as nitrate (Pb(N03)2) 4 to 1000
Manganese, as sulphate (MnSOJ 8 to .2000
Zinc, as sulphate (ZnS04) 8 to 2000
In addition to these seven elements the following were ap-
plied in one concentration only, namely 500 parts per mil-
lion:— barium, as chloride (BaCl2) ; bromine, as potassium
bromide (KBr) ; cobalt, as sulphate (CoSOJ ; chromium, as
potassium chromate (K2Cr04) ; iodine, as potassium iodide
(KI) ; lithium, as sulphate (Li2S04) ; mercury, as mercuric
chloride (HgCl2) ; nickel, as sulphate (MS04) ; silver, as
nitrate (AgN03) ; uranium, as uranyl nitrate (U02(N03)2) ;
and vanadium', as chloride (VC12). All of these elements
except iron were applied to Impatiens sultani, Coleus blumei
196 Symptoms of Poisoning in Plants [394
and View faba as well as to Pelargonium. The first ten
elements (arsenic, boron, copper, manganese, zinc, lead, mer-
cury, iodine, chromium, and barium) were applied also to
Chrysanthemum frutecens, Bryophyllum calycinum and
castor bean (Ricinis communis) . Except as noted, all appli-
cations were in the concentration of 500 parts of the poison-
ous element per million parts of soil. In order to avoid local
injuries to the stem large applications were frequently divided
and added in several portions at intervals of a few days.
The following elements gave no determinable poisonous
effects on any plant, in the concentrations used: arsenic,
barium, bromine, cobalt, copper, lead, manganese, nickel,
silver, uranium, vanadium and zinc. A slight improvement
of color and general condition was noticed in Pelargonium
with manganese and zinc. There was also a slight, but un-
mistakable, stimulation of the growth of this plant by arsenic
in the higher concentrations but this conceivably may have
been due to some chemical action in making more available
the phosphorus or other nutrients in the soil.
Pronounced toxic effects were observed with boron, chro-
mium, iodine, lithium and mercury, and it is interesting
that these effects were largely so specific as to permit imme-
diate recognition of the particular poison by mere inspection
of the plant. Thus on Pelargonium the effect of boron is the
development of dark-green areas, 1 to 5 mm. wide, inward
from the edges of the leaves. This altered strip gradually
dries and hardens, without becoming brown, and the leaf
falls after from one to four weeks. The dark-green coloration
does not extend to the whole leaf. Lithium shows a some-
what similar behavior, but the altered area on the edge of the
leaf is wider and is a light gray-green instead of dark green.
It shows a very characteristic banding of the color in narrow
light and dark lines parallel to the leaf edge. With iodine
the leaves turn yellow on the edges and this yellowing gradu-
ally extends inward over the whole leaf. Not until the leaf
has turned entirely yellow does it fall or wilt appreciably.
Mercury produces a somewhat similar yellowing of the leaves,
395] E. E. Free 197
but wilting begins immediately and the leaf usually falls
long before it is entirely yellow. The first effect of chromium
is a brown discoloration in the vascular bundles of the petioles
and veins. This is followed by a change of the leaf color
to a dark green, and the early fall of the leaves. The regu-
larity and specificity of these changes is attested by many
repeated observations on different leaves and different plant
individuals. Similar specificities were observed with the
plants other than Pelargonium. It seems probable, therefore,
that the recognition of a poisonous agent by the specific symp-
toms of its action is as possible with these plants as with
animal organisms.
Certain features of the localization of injury in the plants
is suggestive of relations to transpiration. For instance, with
boron and lithium on Pelargonium the limitation of injury to
the edges of the leaves implies its occurrence only where the
final evaporation of the water of the transpiration stream
localizes the poison in a concentration sufficient to be toxic. A
similar conclusion follows from the fact that injury occurs
first, and sometimes only, on leaves of moderate age, that is
on those which are in their period of most vigorous transpira-
tion. Younger leaves and older leaves on the same plant are
usually uninjured. Similarly, when a Pelargonium plant
is poisoned but not killed, by either boron, lithium, mercury
or iodine, new leaves produced thereafter do not show injury
while they are young, but develop it after from two to six
weeks of growth. The same observation was made with
boron and iodine on Chrysanthemum. Further confirmation
is the failure of Bryophyllum, which has a very low transpir-
ing power, to show injury with any poison except boron.
Even in this case the injury developed eleven weeks later than
it did on Pelargonium and all the other plants. All of this
evidence suggests that, in the concentrations used, the poisons
were carried into the plant incidentally by the transpiration
stream and produced injury only when and where the evap-
oration of the transpired water increased the concentration of
the poison in a local tissue area. The symptoms observed
198 Aeration [396
with chromium imply that it may form an exception to this
behavior, but even with this element it was observed that
Pelargonium leaves were injured only when of middle age;
young and old leaves being unaffected.
THE EFFECT OF AERATION ON THE GROWTH OF
BUCKWHEAT IN WATER-CULTURES
By E. E. FREE
In connection with other work on the oxygen requirements
of plant roots experiments have been made on the relations
between the degree of aeration of the culture solution and
the growth of buckwheat in water-cultures. The plants were
grown in quart jars in the usual manner, three plants to a
jar. The solution was that found by Shive 1 to be the best
for the growth of buckwheat. The experiment included 18
jars divided into six sets of three jars each. One set, used
as control, was handled according to the usual technique, with
free access of air to the solution. Another set was sealed,
the seal about the young plants being made with a parafme-
vaseline mixture according to the method of Briggs and
Shantz.2 With the third set, a slow stream of air was bubbled
through the culture solution, a bubble about 5 mm. in diam-
eter passing about once a second. The three remaining sets
were treated in the same way with oxygen, nitrogen and
carbon dioxide, respectively. Precautions were taken to re-
move deleterious impurities from the gases. Water evaporated
from the culture solutions was replaced when necessary.
The cultures with oxygen, nitrogen and air showed no de-
parture from the open controls or from the sealed cultures.
1 Shive, John W., " A three-salt nutrient solution for plants."
Amer. Jour. Bot. 2: 157-160, 1915.
2 Briggs, L. J., and Shantz, H. L., "A wax seal method for deter-
mining the lower limit of available soil moisture." Bot. Gass. 51:
210-219. 1911.
39T] E. E. Free and S. F. Trelease 199
Eate of growth and weight of dry matter produced was essen-
tially the same in all. All plants grew to maturity and
nearly all set seed. It appears that the degree of aeration of
the culture solution is without important influence on the
growth of buckwheat under the conditions described; a con-
clusion that may have value in general water-culture prac-
tice. '
It may be added that in the cultures treated with carbon
dioxide the plants sickened and wilted within a few hours
and died within a few days. In one case the stream of car-
bon dioxide was replaced after the first day by a stream of
air. In this case the plants recovered partially but remained
permanently smaller than the other plants of the experi-
ment. ! *
THE EFFECTS OF CERTAIN MINERAL POISONS ON
YOUNG WHEAT PLANTS IN THREE-SALT
NUTRIENT SOLUTIONS
By E. E. FREE and S. F. TRELEASE
A large part of the experimentation which has been done
in the past on the effects of mineral poisons on plants is un-
satisfactory and contradictory, for the reason that the nutri-
ent materials available to the plants, in the soil or nutrient
solution employed, were different in the different experi-
ments. The reactions of plants to the various poisons appear
to vary with such differences in the available nutrients. In
connection with other work on nutrient solutions,, tests have
been made on the effects of certain poisonous elements on
the growth of young wheat plants in water-cultures. The
salt combination used in the nutrient solution was that found
by Shive * to be best for the production of dry weight of
1 Shive, J. W., "A three-salt nutrient solution for plants." Amer.
Jour. Bot. 2: 157-160. 1915. Idem, "A study of physiological bal-
ance in nutrient media." Physiol. Res. I: 327-397. 1915. (Especi-
ally p. 352-364.)
200 Mineral Poisons [398
tops for wheat. The total concentration of the solution corre-
sponded to an osmotic pressure of 1.75 atmospheres at 25° C.
The technique was essentially the same as that employed by
Shive.
The minimum concentrations at which the various poisons
began to produce clearly marked injury, as indicated by
smaller dry weights of tops, are given in the following table.
Concentrations are "given in parts of the poisonous element
per million parts of the nutrient solution. In most cases the
concentration at which injury begins is not sharply marked,
and, therefore, the figures given have only approximate quan-
titative value.
Toxic
Concentration
Element Compound used of element.
p. p. m.
Arsenic trioxide ( As203) 1
Boron borax (Na,B40T) 10
Cobalt sulphate (CoSOJ 7
Copper sulphate ( CuSO4 ) 1
Manganese sulphate (MnS04) 1000
Mercury bichloride (HgCl2) 40
Nickel sulphate (NiS04) 5
Vanadium chloride ( VC12) 20
Zinc sulphate (ZnS04) 100
Experiments were made also with lead, as lead nitrate
(Pb(ISr03)2), and with uranium as uranyl nitrate
(U02(N~03)2), but both of these elements were precipitated
by the constituents of the nutrient solution. The maximum
concentrations obtainable in the solution were approximately
100 parts per million in case of lead and 20 parts per million
in the case of uranium. Neither of these was toxic.
A slight stimulating effect, indicated by greater produc-
tion of tops, was observed with manganese, between the con-
centrations of 4 and 20 parts per million, and with vanadium,
between 2 and 7 parts per million. There was a clear stimu-
lation in the uranium cultures above a concentration of 50
parts per million of uranium, but it is possible that this was
399] E. E. Free and S. F. Trelease 201
due to the nitrate in the uranium salt. No stimulation was
observed with any other of the elements tested.
This failure to secure determinable stimulating effects with
most of the elements is surprising and is contrary to the re-
sults of many previous investigations. It seems possible that
it may be due to the fact that the Shive solution, in the con-
centration and salt proportions employed, is itself slightly
toxic because of its high content of magnesium. This solu-
tion, although it gives the best production of dry wefght of
tops, produces plants many of which show the morphological
modifications characteristic of magnesium poisoning.2 These
observations form one of several bits of evidence which sug-
gest that the best growth of a plant, as measured by produc-
tion of dry matter, occurs only when the plant is slightly
poisoned. It may be a general rule that increased growth
is the first response to agents or circumstances which would
prove injuriously toxic in greater concentration or on longer
exposure.
"We have found some confirmation of this suggestion in our
experiments on the effect of boron on Canada field pea. Using
the Shive solutions containing salt proportions other than
the ones above referred to, and adding borax to these solu-
tions, considerable stimulations were obtained. The experi-
ments need to be extended and confirmed, but the present
indication is that borax is stimulating in those nutrient solu-
tions which contain less magnesium than the one giving great-
est dry weight of tops. In other words, slight poisoning,
such as that caused by magnesium or boron, is essential for
the production of the greatest dry weight of tops. Either
magnesium or boron will serve. Probably other poisons
would be equally efficacious.
2 Shive, loo. tit.. (2), p. 370-374. Tottingham, William E., "A
quantitative chemical and physiological study of nutrient solutions
for plant cultures." Physiol. Res. 1 : 133-245. 1914.
202 Leaf-Product [400
LEAF-PRODUCT AS AN INDEX OF GROWTH IN
SOY-BEAN
By F. MERRILL HILDEBRANDT
It has been pointed out by McLean x that the sum of the
products of the length and breadth of all the leaflets on a
soy-bean plant 4 weeks old is approximately proportional to
the total leaf area of that plant,, and he adds that the leaf
area is itself nearly proportional to the total dry weight of
stem and leaves. The sum just mentioned has been called
the leaf-product by the same writer, his observations being
based on measurements obtained at two stations in Maryland,
Easton and Oakland, in the project carried out during the
summer of 1914 by the Maryland State Weather Service in
co-operation with the Laboratory of Plant Physiology of the
Johns Hopkins University. That project included similar
studies of the relation of plant growth to climatic conditions
at seven other stations in Maryland, besides Easton and Oak-
land, and the present paper aims to bring out the fact that
this interesting relation between leaf-product, leaf area and
dry yield of tops applies generally to the soy-bean data for
all nine stations.
If the method proposed by Livingston 2 and McLean, of
employing the growth rates of standard plants as indices for
the comparison of different climates as these influence plant
growth in general, is to be of value, it is of course necessary
that suitable plant characteristics be chosen for measurement
in determining the growth rates, and it is desirable that the
measurements be such as may be made from time to time
without injury to the plants. The most generally accepted
1 McLean, F. T., "A preliminary study of climatic conditions in
Maryland, as related to plant growth." Physiol. Res. 2: 129-208.
1917.
2 Livingston, B. E., and McLean, F. T., "A living climatological
instrument." Science, n. s. 43: 362-363. 1916.
401] F. M. Hildebmndt 203
criterion of plant growth, dry weight of tops, can be obtained
but once for any individual plant, since the plant is destroyed
during the determination. Also, the accurate determination
of leaf area is very difficult unless the plants are destroyed.
On the other hand, as McLean has emphasized, leaf dimen-
sions may be obtained repeatedly during the development
of the plant without serious danger of inflicting injury. It
may therefore be of considerable importance if leaf area, and
even dry weight, can be satisfactorily estimated for soy-bean
by the employment of the leaf-product as an index.
The general procedure followed in obtaining the observa-
tional data upon which are based the results here considered
has been described by McLean, who conducted all the cultures
personally (see his paper cited above). For the present pur-
pose it is sufficient to state that cultures, each of 6 soy-bean
plants, were started from the seed every two weeks through-
out the summer season, at each of the nine stations employed,
and that plant measurements were taken after about two and
after about four weeks of growth. Dry weight and actual
leaf area were determined only for the four-week periods, the
plants being then destroyed, but the lengths and breadths
of all leaflets were obtained for both the two-week and the
four-week periods. Consequently, to study the correlation
between total leaf area and total leaf -product per plant, only
the four-week data are available, and these are the ones here
considered. Thus, each of the nine stations is represented
by a series of consecutive four-week culture periods, each
period overlapping on to the next preceding and next follow-
ing one. A large number of different sets of climatic con-
ditions is thus represented by the whole series for the nine
stations, which includes 97 4- week culture periods in all.
The leaf measurements here dealt with have all been ob-
tained by the writer from photographic contact prints made
by Dr. McLean from the fresh leaves immediately after these
were removed from the plants. Areas were obtained from the
same prints with a planimeter. The leaflet length was taken
from tip to junction of blade and petiole for each leaflet, and
204 Leaf-Product [402
the corresponding leaflet breadth was measured at the point
of greatest width, at right angles to the long axis of the
leaflet. Since soy-bean leaflets are approximately elliptical
in form and since the area of an ellipse is proportional to
the product of its axes, the leaflet-product (length times
breadth) of any leaflet should be nearly proportional to the
area of that leaflet. Whether this relation may hold during
the growth of the leaflet under different sets of climatic con-
ditions depends upon how nearly the elliptical form is re-
tained. The sum of the individual leaflet-products of any
plant, which is the total leaf -product for that plant, should
be approximately proportional to the total leaf area of the
plant, if the relation given above holds. In the discussion
that follows it will be shown that such an approximate propor-
tionality does exist in the case of the four-week soy-bean
plants.
In order to find out whether the actual area of the leaves
in these cultures was proportional to the leaf-products, the
ratio of the two quantities was worked out for a number of
the stations. It was found that the leaf -product divided by
the leaf area gives a number that varies only slightly from the
value 1.28. In other words, if we measure the two diameters
of the leaflets of a four-week soy-bean plant, multiply these
two numbers, and add the products, a number is obtained
which, when divided by 1.28, closely approximates the actual
leaf area of that plant. Instead of using the sum of the
products of length and breadth as an index of the area per
plant we may use the sum of the squares of the lengths of
the leaflets or the sum of the squares of the breadths of the
leaflets of the plant. The numbers thus secured do not, how-
ever, bear as nearly constant a ratio to the actual leaf area
as does the total leaf-product, and hence neither is as satis-
factory an index of the area as is the leaf -product itself.
One of the most interesting properties of the four-week
soy-bean plant is that the dry weight of stem and leaves is
proportional, approximately, to the total leaf area. Having,
therefore, a means by which the leaf area may be conveniently
403] F. M. Hildebrandt 205
measured, it is possible to calculate the dry weight of the
plant approximately, by multiplying the leaf-area by the
proper constant. The proportionality between the weight of
the plant and its leaf area is not quite so constant as that
between leaf area and leaf product, but in the great majority
of cases the variation in the ratio of dry weight to leaf area,
from a constant value, is less than 10 per cent. The rela-
tions given hold over a very wide range of climatic conditions
and for plants varying in height from 2 or 3 centimeters
to 18 or 20 centimeters. Since none of the plants in these
experiments were grown to maturity, it is impossible to say
whether this relation holds up to that time.
From the foregoing facts it may be concluded that the dry
weight and leaf area of soy-beans 4 weeks old from the seed
can be determined approximately from their leaflet dimen-
sions. Soy-bean should therefore be very suitable for use as a
standard plant for the measurement of climate in the man-
ner suggested by Livingston and McLean, since the rate of
its growth can be approximately determined from easily ob-
tained leaf measurements. Also, the properties of soy-bean
given above should make it a useful plant for any piece of
physiological research in which it is desired to know approxi-
mately the dry weight of the plant used, at various stages
of its development.
A METHOD FOR APPROXIMATING SUNSHINE INTENSITY
FROM OCULAR OBSERVATIONS OF CLOUDINESS
By F. MERRILL HILDEBRANDT
Air temperature, the evaporating power of the air, and
sunshine intensity may be considered the main climatic con-
ditions affecting plant growth and one of the first essentials
in ecological, agricultural, and forestal studies is some means
by which these may be measured in the field. We are al-
ready provided with instruments for measuring the first two,
206 Sunshine Intensity [404
but the means thus far available for measuring sunshine in-
tensity are difficult to apply in field studies. A method is
here presented by which a roughly approximate index of sun-
shine intensity during any period for any station may be
made from records such as are kept by the observers of the
II. S. Weather Bureau.
The total heat equivalent of the actual sunshine for any
given period at a station is primarily a function of three
terms: (1) the maximum possible number of hours of sun-
shine (determined by latitude and season) ; (2) the mean
intensity of full sunshine for the period and station, ex-
pressed in terms of heat; (3) the condition of the sky>
whether overcast, partly overcast or clear. The daily values
for the first two of these terms vary in a regular manner
throughout the year at any given place, and the ones for the
third term are roughly stated in the observer's records, as just
mentioned. It was desired to combine these three terms so
as to get approximations of sunshine intensity for a number
of different stations in Maryland for the summer of 1914,
in order to make comparisons of the summer march of sun-
shine intensity with that of corresponding measurements of
plant growth. This has been accomplished in the manner
described below.
The first two terms are combined in the ordinates of the
graph given by Kimball1 for the maximum possible total
radiation received per day at Mount Weather, Virginia.
Since this station is at about the same latitude as the stations
in Maryland, the ordinate values may be taken as approximate
measures of the total radiation intensity for the corresponding
dates at any place in the state. These values represent the
total amount of heat, expressed in gram-calories per square
centimeter of horizontal surface exposed, received from the
sun and sky on clear days at Mount Weather. The method
1 Kimball, Herbert H., " The total radiation received on a hori-
zontal surface from the sun and sky at Mount Weather. Monthly
Weather Rev. 42: 474-487. 1914. (See especially fig. 8, p. 484).
405] F. M. HiUebrandt 207
of using the graph and a weather observer's report for estimat-
ing sunshine will be best shown by an example.
Suppose it is desired to estimate the average daily sunshine
intensity for some station in the general region of Mount
Weather, for the first week of August. The average ordinate
value for this week is first obtained from KimbalPs graph.
For periods as short as a week or two this may be done by
averaging the values for the first and last days of the period,
since the curve may be taken as a straight line for such short
intervals. From the report of the weather observer at the
place in question, the number of clear, partly cloudy, and
cloudy days is next determined for the days August 1 to
August 7, inclusive, and some arbitrary weighting is given
to each kind of day. We may, for instance, call clear days
whole days of sunshine, partly cloudy days half days of sun-
shine, and assume that cloudy days are days without any sun-
shine. The scheme of weighting adopted must, of course, be
adhered to in all the estimates made for different periods and
stations. The system of weighting given above was used in the
studies for which this method of approximating sunshine was
developed. By summing these weighted daily values a num-
ber is obtained which represents the equivalent number of
clear days for the period considered. Suppose, in the example
selected, that this equivalent number of clear days is 3.5,
which is 0.5 of the total number of days in the period. The
latter value may be termed " the coefficient of clear weather."
By multiplying the average daily intensity value for clear
days, as obtained from the curve, by this coefficient of clear
weather a number is secured that is a rough approximation
of the average daily sunshine intensity for the week.
While it is certain that solar radiation affects plants in
other ways than through its heating effect, it is no less cer-
tain that by far the greater part of the energy of sunshine
absorbed by plants is converted into heat (largely as latent
heat of the vaporization of water), and it seems probable that
the other effects produced upon the plant may be more or less
proportional to the total energy equivalent of sunshine. The
208 Moisture Equilibrium [406
method of measurement of light here given, although it is only
a rough approximation and depends on the heating effect of
the sunshine, has been shown, as a matter of fact, to give
numbers rather definitely correlated with plant growth. It
has been found, for instance, that the amount of dry sub-
stance produced per unit of leaf area in young soy-bean
plants decreases from the beginning to the end of the growing
season, in a manner which generally parallels a corresponding
fall in the light intensity values as determined in the manner
described above.
MOISTURE EQUILIBRIUM IN POTS OF SOIL EQUIPPED
WITH AUTO-IRRIGATORS
By F. S. HOLMES
While the auto-irrigator devised by Livingston 1 has been
employed by several writers,2 for maintaining uniform mois-
ture conditions in potted soils, the details of adjustment re-
quired by this device, for different soils and for maintaining
different moisture contents, remain still to be worked out.
In order to throw some light upon this general question, a
study of three different soils was undertaken to determine
the relation between the equilibrium point of the soil-moisture
content and the number of irrigator cups employed.
One soil was a medium-fine white sand, one was a light
1 Livingston, B. E., " A method of controlling plant moisture."
Plant World II: 39-40. 1908.
2 Hawkins, Lon A., " The porous clay cup for the automatic water-
ing of plants." Plant World 13: 220-227. 1910. Transeau, E. N.,
" Apparatus for the study of comparative transpiration." Bot. Gaz.
52: 54-60. 1911. Livingston, B. E., and Lon A. Hawkins, "The
water relation between plant and soil." Carnegie Inst. Wash. Pub.
204: 5-48. 1915. Hibbard, R. P., and 0. E. Harrington, "Depres-
sion of the freezing-point in triturated plant tissues, and the mag-
nitude of this depression as related to soil moisture." Physiol. Res.
I: 441-454. 1916.
407] F. S. Holmes 209
clay loam, and the third was a mixture, of equal parts, by
volume, of the other two. Pots of each kind of soil were
equipped with auto-irrigators having respectively one, three
and five porous cups, thus giving nine combinations. The
containers were tinned sheet-metal cylinders approximately
15 cm. in diameter and 17 cm. in height. The porous cups
were evenly distributed within the soil mass, when but one
was used it occupied the center. A mercury tube was so ar-
ranged that all water entered the soil against a pressure of
from 5 to 6 cm. of a mercury column. Evaporation was pre-
vented by sealing covers on the containers with plastiline.
The cylinders were filled to a uniform depth of 16 cm., an at-
tempt being made to secure as uniform packing as possible
throughout the entire series.
Weighings of the containers were made at intervals of two
or three days, for the first twenty days, and thereafter at
weekly intervals, to determine the rates at which water was
being absorbed and to approximate the moisture content of
the soil. Approximately three-fourths of the water taken
up by the loam and by the sand-loam mixture occurred dur-
ing the first ten days, but the sand took up only about one-
half of its total amount in the same period. Approximate
equilibrium of the soil moisture content was reached in about
seventy-five days, in the case of the loam; in about eighty
days in the case of the mixture ; and in about ninety days in
the case of the sand. The number of porous clay cups em-
ployed seemed to have no influence upon the length of time
required for the attainment of equilibrium by either the loam
or the loam-sand mixture. With the sand, however, the
number of cups appeared to influence the length of this time
period. With three cups equilibrium was reached sooner than
with one, and with five sooner than with three.
When the weighings of the cylinders and observations on
the water reservoirs showed that the soil had ceased to absorb
water, the cylinders were opened and samples were taken for
soil-moisture determinations. Two 1-cm., full-depth cores
were taken from each container, one core from as near a cup
14
210 Moisture Equilibrium [408
as possible, the other as far removed as possible. The aver-
age of the two was taken to be representative of the entire
soil mass. Each sample was removed and dried in eight
2-cm. sections, so that it was possible to study both the ver-
tical and horizontal distribution of the soil moisture in the
cylinder. There was a horizontal as well as a vertical varia-
tion of small magnitude in the soil-moisture content of
all the cylinders, the water content being almost always
somewhat higher near the cups and at the bottom of the soil
mass. The distribution of the moisture, both horizontal
and vertical, was more uniform in the sand-loam mixture
than in the sand, and also more uniform in the loam than
in the mixture. The number of porous cups used had very
little influence, if any, upon the soil moisture content of the
loam; it varied as 100 : 106 : 103, for the containers having
one, three and five porous cups, respectively. This influence
of the number of cups was more pronounced in the case of
the sand-loam mixture, the variation, with one, three and
five cups, being 100 : 147 : 168. With the sand there was a
still more marked effect, the moisture contents for the three
cup numbers being 100 : 191 : 277 in this case. These vari-
ations are all smaller than the corresponding variation? in
the value of the ratio of cup number to soil mass, these values
varying as 100 : 321 : 576, for all three soils. For the con-
tainers with three cups the actual average soil moisture con-
tent (on the basis of dry weight) was 11.0 per cent, for the
loam, 5.2 per cent, for the mixture, and 1.1 per cent, for the
sand.
With the pressure here used (averaging 5.5 cm. of a mer-
cury column) the soil moisture content at equilibrium was
too low for plant cultures in the sand and perhaps also in the
sand-loam mixture. In the loam, however, it was surely high
enough to supply plants with the water necessary for their
growth under ordinary greenhouse conditions.
409] E. 8. Johnston 211
SEASONAL VARIATIONS IN THE GROWTH-RATES OF
BUCKWHEAT PLANTS UNDER GREENHOUSE
CONDITIONS
By EAEL S. JOHNSTON
Seasonal variations in greenhouse plants are of considerable
importance to plant growers as well as to experimenters in
plant physiology,, but it is especially with reference to physi-
ological experimentation that this study was undertaken.
When it is necessary to repeat an experiment on plant growth
it often occurs that the results of the second experiment are
in more or less pronounced disagreement with those of the
first. Since the controlled external conditions must be re-
garded as the same- for both experiments, such disagreement
appears to be related either to initial differences in the plants
used (internal conditions) or to uncontrolled external con-
ditions as these vary with the season. The first of these pos-
sibilities is probably not as important as the second in most
cases, for care is usually taken to select plants for the second
experiment that are apparently similar to those used for the
first. While this problem of similarity of internal conditions
of different lots of plants is a very difficult one and is hardly
susceptible of quantitative study at the present time, it is
quite possible to carry out studies on the relation of growth
to the usually uncontrolled (or only partially controlled)
external conditions of a greenhouse., as these conditions
change throughout the year. A portion of the results ob-
tained from such study are here presented.
A set of similar water cultures was started every two weeks
and each was continued for a period of four weeks, so that
the periods of successive sets overlapped. A single set con-
sisted of ten plants, each suitably supported in a glass jar con-
taining about 425 cc. of nutrient solution. These jars were
covered, to exclude most of the light from the plant roots.
The solution was renewed at the middle of each four-week
212 Variations in Growth-Rates [410
period. At the end of each week several different kinds of
measurements of the plants were made, and the data thus
obtained were studied to bring out the seasonal variations in
growth-rates. Since the solutions were alike for all sets and
the seedlings used were selected for likeness, it is fair to sup-
pose that observed differences in growth-rates, between the
different sets of cultures, must have been mainly due to fluc-
tuations in the uncontrolled conditions of the surroundings,
such as temperature, light and the evaporating power of the
air.
The experiments were carried out in one of the experiment
greenhouses of the Laboratory of Plant Physiology. Xo
artificial shade was applied to the greenhouse. Two sets of
cultures were always carried out simultaneously, one under
unmodified greenhouse conditions and the other in a cheese-
cloth chamber in the greenhouse, but the data obtained from
the chamber cultures will not be dealt with in the present
paper. A continuously rotating table 76 cm. in diameter was
used in each case, the jars standing near the margin of the
table.
Japanese buckwheat, Fagopyrum esculentum Moench., was
employed, and Shive's * three-salt nutrient solution, no.
R 4C2 (total osmotic value 1.75 atmospheres), was used
throughout the entire series. Aside from renewing the
solution at the middle of the four-week period, water was
always added at the end of the third week of growth, to bring
the solution back to its original volume. When the transpi-
ration rates were excessive a still further addition of water
was made during the fourth week of growth, in order to pre-
vent the root systems from becoming unduly exposed. The
first experiment began Feb. 14, 1916.
Of the plant characteristics measured at the end of each
four-week period of growth, only stem height, total dry weight
and total area of the leaves (one surface only) are here con-
1Shive, John W., "A study of physiological balance in nutrient
media." Physiol. Res. I: 327-397. 1915.
411]
E. 8. Johnston
213
sidered, the values obtained being expressed as averages per
plant, for each of the four-week periods. The temperature
conditions, the evaporating power of the air and the intensi-
ty of radiation were recorded for each of the two exposures,
but these are left out of the present consideration.
The results obtained from these three plant measurements
are shown in the accompanying table, wherein all the values
are expressed in terms of the corresponding value for the
period ending May 22. In this table the dates of beginning
and ending of the several culture periods are shown in the first
two columns. Each value given in the table represents an
average growth-rate representing a single plant, for a time
period of 28 days.
EXPERIMENTAL DATA
Period
Stem
Total
Total
Av'ge of
Beginning
Ending
Height.
Dry Wt.
Leaf Area
Wt. & Area
Feb. 14
Mar. 13
.73
.50
.63
.57
Feb. 28
Mar. 27
.83
.62
.81
.72
Mar. 13
Apr. 10
.85
.72
.77
.75
Mar. 27
Apr. 24
.94
.80
.76
.78
Apr. 10
May 8
.98
.89
.76
.83
Apr. 24
May 22
1.00
1.00
1.00
1.00
(67.5 cm.)
(1.338 g.)
(213.5 sq,
, cm.)
May 8
June 5
.93
.91
.93
.92
May 22
June 19
.83
.93
.98
.96
June 5
July 3
.73
.93
1.00
.97
(214.1 sq.
cm.)
June 19
July 17
.77
.88
.88
.88
July 3
July 31
.97
.91
.92
.92
July 17
Aug. 14
1.04
.82
.83
.83
July 31
Aug. 28
.91
.67
.77
.72
Auff 14
Sept. 11*
•*••*• *-*g» -LTE
Aug. 28
Sept. 25
1.07
.76
.70
.73
Sept. 11
Oct. 9
.97
.55
.58
.57
Sept. 25
Oct. 23
.78
.34
.43
.39
Oct. 9
Nov. 6
.79
.36
.51
.44
The different kinds of growth-rates are seen to vary inde-
pendently, from period to period, but two of the growth
Data not obtained because of insect injury to plants.
214 Variations in Growth-Rates [412
criteria,, weight and area, show variations that correspond
rather closely. Both of these show high rates for the sum-
mer and low ones for the spring and autumn. Judged by
dry weight of plant produced the growth-rate reached its
maximum (1.34 g. per plant, in 28 days) with the period
ending May 22, but this value remains high until after the
period ending July 31. Judged by the total leaf area, the
rate does not attain its maximum (214 sq. cm, per plant, in
28 days) until later, this occurring with the period ending
July 3, but this value is high for the three preceding periods
and for the two following. Roughly speaking, it may be said
that these two criteria give rates that are proportional, and
that they agree in indicating a period of very rapid growth,
extending from about May 8 to about July 17. Before the
period with its middle at May 8 the rates are lower, forming
a generally ascending series, from the very low values of the
early spring, and after the period with its middle at July 17
they decrease rapidly (with a low secondary maximum indi-
cated for the period ending Sept. 25) to very low values in
the autumn.
The rates of growth in height fail to show this sort of
seasonal march; the maximum rate (49 cm. per plant, in 28
days) being shown for the period ending July 3, but this
rate also has very low values for the periods ending March
13, Oct. 23 and JSTov. 6. By this criterion, the maximum for
the period considered (72.5 cm. per plant, in 28 days) occurs
with the period ending Sept. 25, but pronounced secondary
maxima are shown for the periods ending May 22 and Aug.
14. This rate of growth in height appears to vary consider-
ably from period to period, but in a manner entirely inde-
pendent of the general advance of the season and quite inde-
pendent of the variations in rates of increase in dry weight
and in leaf area. As far as these data go, it therefore ap-
pears that there is nothing in the usually uncontrolled ex-
ternal conditions of a greenhouse in this climate, that may
be expected to produce a regular march of growth-rates in
413] E. 8. Johnston 215
height, for healthy buckwheat plants, during the spring, sum-
mer and autumn.
McLean 2 has pointed out the approximate proportionality
of the rates of production of dry weight and leaf surface,
for the first four weeks of growth of soy-bean plants, and he
also found that the rate of stem elongation varied quite differ-
ently from the rates of production of dry weight and surface.
It may be of- fundamental significance that two plants as
widely different, in many other respects, as are buckwheat and
soy-bean, exhibit these remarkable agreements in the manner
of variation in these three growth-rates with differences in
the climatic conditions of the environment.
The general agreement between the seasonal variations
shown by the rates of increase in dry weight and in leaf area
is so marked that it appears quite permissible to combine these
two criteria by averaging their relative values, to give a single
value representing both together, and the averages so derived
are given in the last column of the table. Of course, these
two measurements of growth-rate are not directly commensu-
rable, and the average values here introduced are to be re-
garded merely as numerical indices of the rates of growth.
This value has its maximum (1.00) for the period ending
May 22, and it of course shows high value for the five fol-
lowing periods. Its minimum value (0.39) occurs for the
period ending Oct. 23.
Of course there are many other considerations to receive
attention in a study of this sort, but it already seems clear
that a regular and pronounced seasonal variation in the rates
of production of dry weight and leaf area may be expected in
healthy buckwheat plants growing in a greenhouse in this
kind of climate, although the same nutrient medium is al-
ways employed. If the weight-area indices be represented
2 McLean, Forman T., "A preliminary study of climatic conditions
in Maryland, as related to plant growth." Physiol. Res. 2: 129-208.
1917.
216 Variations in Growth-Rates [414
graphically they give only comparatively slight variations
from a smooth curve and the actual graph may readily be
smoothed to give such a curve. After this has been done the
ordinates of the smoothed curve, corresponding to the various
culture periods, may be measured, and the series of graphi-
cally derived values thus obtained may be taken as a tentative
scale to indicate approximately the relative growth-rates to be
expected for this plant in these general surroundings. Of
course, the seasonal march of the climatic conditions in this
particular greenhouse must be expected to vary from year to
year, and it surely varies from greenhouse to greenhouse;
nevertheless, the tentative scale derived as just described may
be of value in several ways.
For the first sixteen four-week periods of the present
study, beginning with Feb. 14, as given in the table pre-
sented above, these relative seasonal indices of growth-rate
(by either dry weight or leaf area, which appear to be propor:
tional, or by their average) are respectively as follows : 61, 71,
79, 86, 91, 96, 99, 100, 99, 96, 92, 87, 81, 75, 68, 61. In this
scale of growth-rate values the maximum (100) occurs for
the period ending June 19, and it represents actual average
growth-rates, as obtained in this study, of 1.24 g. of dry
weight and 209 sq. cm. of leaf area (one surface only), per
plant, per period of 28 days. While these derived results
are extremely tentative and probably only very roughly ap-
proximate, it is clear that we have here a new kind of descrip-
tion of the climatic conditions of this greenhouse for the
spring, summer and autumn of 1916, these conditions and
their seasonal march being described in terms of their ability
to produce dry material and leaf surface in the standard plant
here employed.
By such a method as this the climatic plant-producing
power for any four-week period may be directly compared
with that of any other similar period, no matter when or
where these periods occur, the standard plant being used as an
automatically integrating instrument for the measurement of
415] W. E. Tottingham 217
the effective climatic conditions. This general method for
the comparative study of climatic conditions has been sug-
gested by Livingston and McLean 3 and a first attempt at its
employment was carried out by McLean in the paper already
mentioned.
ON THE RELATION OF CHLORINE TO PLANT GROWTH
By W. E. TOTTINGHAM
As a result of experiments conducted early in the develop-
ment of the water-culture method, chlorine has been con-
sidered as one of the unessential elements for the growth of
plants in general. Nevertheless, all seeds contain more or
less of this element and in no instance has a plant been limit-
ed to this original source of chlorine through successive gen-
erations, so that it may still be said that the question here
raised has never been really tested. Practically all soils con-
tain considerable amounts of chlorine in the form of chlorides
and its occurrence in plants appears to be confined to this
form. That this element may have important effects under
some conditions, when applied as an agricultural fertilizer,
is indicated by a common practice in some parts of Europe,
of adding common salt to stimulate the growth of mangel-
wurzel and of mixed meadow grasses, but the manner in which
this effect is produced has not been made clear. It has been
observed that unrestricted application of chlorides may lead
to poisoning of the soil, and agriculturists have been advised
specially against the use of potassium chloride as a source of
potassium for tobacco, the potato and the sugar beet. Euro-
pean investigators have reported a decreased content of starch
in the potato tuber as a result of the substitution of this salt
for potassium sulphate.
3 Livingston, B. E., and McLean, F. T., "A living climatological
instrument." Science, n. s. 43: 362-363. 1916.
218 Chlorine and Plant Growth [416
The investigations here considered in a preliminary way
were planned to supplement our knowledge of this subject.
They are as yet in early stages of progress, having been begun
under the auspices of the Wisconsin Agricultural Experiment
Station. It was purposed to measure the responses of various
plants, in form and in the weight of plant material produced,
to the application of certain chlorides, and to determine any
specific results brought about by this application of chlorine,
upon the chemical composition of the plants. Greenhouse
cultures were grown in nutrient solutions, in pure sand and
in Miami silt loam, and field cultures were grown in loam. It
may be said of these greehouse cultures, which were partly
carried out in the winter, that, while growth is retarded by the
decreased light intensities of the winter months, the partial
control of climatic and soil conditions in such greenhouse cul-
tures assures more reliable comparative results than are usually
derived from field plots, with their natural fluctuation of
climatic conditions from season to season and of fertility from
plot to plot.
In the water-culture experiments, in the greenhouse, the
plants were grown to maturity, in either Tottingham's or
Knop's nutrient solution,1 containing Ca(ISr03)2, KN03,
MgS04 and KH2P04, in proper proportions, with a trace of
iron as FeP04. The former had a total osmotic concentration
value of about 1.75 atmospheres (0.4 per cent, of salts by
weight) and the total osmotic value of the latter was about
0.9 atmospheres (0.2 per cent, of salts by weight). In some
cases chlorine was introduced by replacing the MgS04 of the
4-salt solution with a molecularly equivalent quantity of
MgCl2, in other cases KN03 was replaced by KC1, and in
still other cases NaCl was superimposed upon the salts usual-
ly present. Replacement of MgS04 by MgCl2 resulted in an
increased length of roots, for pea, wheat and clover, amount-
Nottingham, W. E., "A quantitative chemical and physiological
study of nutrient solutions for plant cultures." Physiol. Res. I :
247-288. 1914.
417] W. E. Tottingham 219
ing to from 100 to 300 per cent. This gain in root length
was correlated with somewhat smaller gains in dry weight.
With wheat and clover the production of dry weight of tops
was depressed by this treatment but the percentage of nitro-
gen contained in the dry tops was unaffected. It will be
noted that the interpretation of these effects is complicated
by the fact that sulphur was absent where chlorine was pres-
ent in the solution.
Buckwheat was grown in Knop's solution modified by hav-
ing KN03 partly or wholly replaced by KC1, thus avoiding
the omission of sulphur. Such treatment led to a slightly
increased production of stem and root when the replacement
was only partial, but complete replacement depressed the root
length and the dry weight of roots and leaves, the amount of
water lost by transpiration being proportionately decreased.
Total replacement of KN03 by-Nad depressed growth more
than when KC1 was used and transpirational water loss was
more than proportionately decreased. Comparison with the
necessary control solutions indicated that this effect is to be
considered specific for the NaCl molecule, an observation
which adds to the accumulating evidence that molecules must
be taken into consideration, and not ions only, in dealing
with the relations between the plant and the solutes of a
nutrient solution. The conclusion of earlier investigators,
that chlorine must be added to the nutrient solution for the
complete development of buckwheat, finds no support in the
present work.
The sand cultures of this study (also in the greenhouse)
were conducted on 20-kilogram portions of sand, in open
boxes with paraffined inner surfaces. The insoluble salts
were incorporated with the dry sand and the others were
added in successive portions of solution. The total applica-
tion of salts was about 0.25 per cent, of the dry weight of the
sand. With mangel-wurzel, an increase of from 40 to 120
per cent, in the dry weight of roots resulted from the applica-
tion of KC1 in a complete fertilizer ration, but greater in-
220 Chlorine and Plant Growth [418
crease followed where NaCl was superimposed upon the usual
complete ration.
For the greenhouse cultures in Miami silt loam, fifteen or
twenty kilograms of air-dry soil were employed, in cypress
boxes, the salts being added as in the case of the sand cul-
tures. The total application of salts approximated from 0.06
to 0.15 per cent, of the dry weight of the soil.
The sugar beet produced 50 per cent, more dry substance
(root) when chlorine was included with the usual salt ration
than when the ration without chlorine was used. The
glucose content of the root was increased somewhat, percen-
tagely on the basis of dry weight, but the sucrose content was
uninfluenced by this treatment. Preliminary experiments
with the radish indicate that it is little affected by the chlorine
supply, while the growth of the carrot is stimulated and that
of the parsnip is depressed as regards content of dry matter
and percentage of sugars. Similar experiments with the po-
tato (" Triumph " and " Eural New Yorker " varieties) gave
the same dry weights of tubers, whether potassium was sup-
plied as the chloride or as the sulphate.
In the field experiments, sugar beet roots showed an increase
of from 10 to 30 per cent., by weight, where NaCl was ap-
plied to the soil at the rate of from 260 to 520 pounds per
acre, as compared with those of the unfertilized plot. The
glucose content was increased, but that of sucrose was unaf-
fected by this treatment.'
The potato (" Triumph " variety) produced the same yield,
both of total and marketable tubers, whether supplied with
potassium as KC1 or as K2S04 , in the complete fertilizer
ration. The addition of NaCl without other salts depressed
the yield. Another experiment with potato ("Eural New
Yorker" variety) showed that the starch content and cook-
ing qualities of the tuber were the same whether potassium
was supplied as KC1 or as K2S04, in the complete fertilizer.
Fertilization with NaCl alone gave tubers of lower starch
content and poor quality. It thus appears that the depress-
419] W. E. Tottingham 221
ing effect of chlorine, as reported2 for starch content and
cooking quality of potato tubers, does not obtain under all
conditions of culture, and fails to make itself manifest with
the climatic and soil conditions of these experiments.
The results outlined above leave the question of the in-
fluence of the chlorine ion and chlorides upon plants still in
a very complicated and unsatisfactory condition. Perhaps
the most valuable general conclusion that can be drawn from
a review of all the work so far reported upon this subject, is
that the influence here considered appears to be impossible
of any general statement. It appears that the effect of
chlorine upon any given plant depends upon the nature of
the plant, upon the soil conditions (aside from chloride con-
tent) and upon the conditions of the surroundings generally
classed as climatic. It may be that each particular case of
acceleration or retardation of growth processes by chlorine
presents a special problem, and that broad generalizations
are not to be expected until much progress has been made
toward the interpretation of environmental complexes as a
whole ; for the present, we are constrained to study these con-
ditions piecemeal. It seems that the promise of progress in
these very complicated problems of agricultural science lies
largely in more complete experimental control of the very
numerous conditions that make up the environment of the
plant. It is the summed or integrated effects of all of these
that is registered by our plants in growth and crop produc-
tion.
2 For example, see: Siichting, H., " Ueber die schadigende Wirkung
der Kalirohsalze auf die Kartoffel." Lcmdw. Versuchsst. 61: 397-
449. 1905.
222 Salt Proportions [420
A STUDY OF SALT PROPORTIONS IN A NUTRIENT
SOLUTION CONTAINING CHLORIDE, AS RELATED
TO THE GROWTH OF YOUNG WHEAT PLANTS
By S. F. TRELEASE
Chlorine has been considered an unnecessary element in the
nutrition of most plants,, but it seems to have produced a
beneficial influence in certain cases that have been recorded.
There is some practical as well as scientific interest in the
question thus raised, since potassium chloride is frequently
used as an agricultural fertilizer, and the influence of the
chlorine thus put into the soil may not be without impor-
tance. In the experiments of which this is a preliminary
report the chlorine ion was introduced into nutrient solutions
that already contained all the essential elements usually ab-
sorbed by plant roots. These essential elements (N, S, P,
Ca, Mg, K, and Fe) may be supplied to the young wheat
plants as a nutrient solution containing the three salts
Ca(N03)2, MgS04, and KH2P04, with a trace of iron as
FeP04. To ' introduce chlorine, KC1 was added to the
list just given, thus making a 4-salt solution. A solu-
tion made from these four salts was used by Knop and
Nobbe, and Grafe * recommends these same salts as most gen-
erally useful. Detmer2 employed one set of proportions of
these -four salts, and this solution has been designated by Tot-
tingham 3 as Detmer^s solution. In the experiment s consid-
ered in this paper the same general methods were used as were
1 Grafe, V. " Ernahrungsphysiologisches Praktikum der hoheren
Pflanzen." Berlin, 1914.
2 Detmer, W., " Practical plant physiology." Translated by S. A.
Moor. London, 1898.
3 Tottingham, W. E., "A quantitative chemical and physiological
study of nutrient solutions for plant cultures." Physiol Res. I :
133-245. 1914.
421] 8. F. Trelease 223
employed by Tottingham and by Shive.4 The total concen-
tration of the nutrient solution corresponded to an osmotic
pressure of approximately 1.6 atmospheres at 25° C., and the
relative proportions of the four component salts were varied
in all possible ways, by increments of one-tenth of this total
concentration. Eighty-four different solutions were thus in-
cluded in each complete set; all of these had approximately
the same total osmotic concentration, but no two had the
same relative proportions of the four component salts. Six
plants were grown in each culture, and the solutions were
renewed every four days.
The various salt proportions proved to be very different in
their ability to produce growth of the young wheat plants.
As has been found by other writers, the solution giving the
greatest dry yield of tops is not the one giving the greatest
yield of roots, and the solution producing the highest dry
weight of tops and roots together has still another set of salt
proportions. The highest dry yield of tops was obtained
with the following partial volume-molecular concentrations
of the four main constituent salts: 0.0067M KC1, 0.0138M
KH2P04, 0.0047M Ca(N03)2, and 0.0081M MgS04. A
trace of iron was, of course, added, as a suspension of ferric
phosphate.
This highest yield of wheat tops with the 4-salt solution
containing chlorine was not higher, however, than was ob-
tained, in these experiments, with the best salt proportions,
without chlorine, of the Birner and Lucanus (Shive) 3-salt
solution and of the Knop (Tottingham) 4-salt solution. If
the best salt proportions are used in all three cases these three
very different types of solutions give practically the same
result. It therefore appears to be impossible to improve the
growth of young wheat plants, as this occurs in Shive's and
Tottingham's best salt proportions, by the introduction of
4 Shive, J. W., "A three-salt nutrient solution for plants." Amer.
Jour. Bot. 2: 157-160. 1915. Idem, "A study of physiological bal-
ance in nutrient media." Physiol. Res. I: 327-397. 1915.
224 Salt Proportions [422
chlorine into the solution. Furthermore, the best 4-salt solu-
tion with chlorine contains the three essential salts in nearly
the same proportions as those in which they occur in Shive's
best 3-salt solution, which has the following composition:
0.0180M KH2P04, 0.0052M Ca(N03)2, and 0.0150M MgS04.
The main difference in this respect lies in the Mg/Ca quoti-
ent; in Shive's best solution this quotient has the value 2.88,
and in the best 4-salt solution with chlorine it has the value
1.72. Both are characterized by relatively high proportions of
KH2P04, and low proportions of Ca(N03)2, which is rather
surprising, since many nutrient solutions heretofore proposed
have a relatively high concentration of Ca(N03)2. In gen-
eral, the occurrence of the morphological leaf modifications
tions recognized as magnesium injury in such series as these
(Tottingham, Shive) was not altered by the presence of the
chlorine ion in the solution.
A marked improvement over Detmer's salt proportions was
obtained in the present study. The best solution gave an in-
crease in dry weight of tops of 27 per cent, and 20 per cent.,
respectively, over the yields obtained in two solutions of the
present series closely resembling Detmer's in salt proportions.
An even more marked improvement over the growth obtained
with Detmer's exact proportions is reported by Shive, for his
best 3-salt solution, which, as has been mentioned, gave prac-
tically the same yield as did the best 4-salt solution used in
this study.
While it seems impossible to obtain higher top yields of these
plants in the 4-salt solution containing chlorine, than in the
3-salt solution without this element, it should nevertheless be
remarked that the presence of chlorine may diminish to some
extent the retarding effect produced by the three salts of the
essential elements when these are not in the best proportions.
Thus, if we start with an unbalanced. 3-salt solution, a proper
addition of chlorine may sometimes accelerate the growth of
the plants. The addition of a non-essential element may im-
prove the physiological properties of a solution containing the
essential elements in improper proportions.
423] 8. F. T release 225
Perhaps the main result of this study is, in general, that
no matter whether we employ (1) the three salts KH2P04,
Ca(X03)2, and MgS04, (2) the four salts KH2P04,
Ca(X03)2, MgS04, and KX03, or (3) the four-salts KH2P04,
Ca('N03)2, MgS04, and KC1, if we use the best proportion*
of the salts in each case we may expect to obtain about the
same growth. This generalization has an important bearing
on the whole problem of physiological balance in nutrient
solutions and furnishes what may be important suggestions
bearing on our general conceptions of conditional control and
conditional optima for plant activities.
THE RELATION OF THE CONCENTRATION OF THE
NUTRIENT SOLUTION TO THE GROWTH OF YOUNG
WHEAT PLANTS IN WATER-CULTURES
By S. F. TRELEASE
In these experiments the salt proportions were the same in
all the different solutions of each series, but the solutions
differed from each other in total concentration. Three series
of cultures, all carried out at the same time, are considered,
each series including a concentration range of from 0.5 to 7.0
atmospheres. A different set of salt proportions was used in
each series. Six plants were grown in each culture and the
cultures were in duplicate, upon a rotating table. The ex-
periment lasted for 32 days, from January 23 to February
24, 1917, the solutions being renewed every 4 days.
In the first series the nutrient solutions contained the 4
salts KH2P04, MgS04, KC1, and Ca(X03)2 in the follow-
ing relative molecular proportions: 1.000, 0.587, 0.485, 0.341.
The average dry weight of tops and the average total water
loss by transpiration, for six plants, are shown in the follow-
ing table, whch also shows the total concentration employed
in all three series.
Concentration of Nutrient Solutions [424
Concentration., Dry Weight, Tops. Transpiration.
atm. grants^ GO.
0.5 0.926 651
1.0 0.947 618
1.6 ' 1.152 646
2.5 1.117 554
3.5 1.030 468
4.5 0.904 386
5.5 0.821 311
7.01 0.769 246
For this particular set of salt proportions the maximum
yield of tops was obtained when the nutrient solution had a
total osmotic concentration of 1.6 atm. With lower con-
centrations growth was considerably less, as is also true, and
to a greater degree, with concentrations above the optimum.
Between the concentrations 1.6 and 7.0 atm. the dry weight
of tops is approximately a linear function of the concentra-
tion, the dry weight decreasing as the concentration increases.
The transpiration values show the same general relation to-
the concentration, except that below 1.6 atm. the decrease is
less clearly shown; in fact, with a concentration of 0.5 atm..
the transpiration is slightly higher than with 1.6 atm.
In the second series the culture solutions were the same
as those just described, except that KC1 was not included,
In these cultures the relations of dry weight and transpira-
tion, to total concentration, were essentially the same as in
the cultures of the first series, with KC1.
In the third series the salts used were the same as in the
first, but in different relative molecular proportions, as fol-
lows : 1.000, 1.155, 7.282, 0.699. The relation between trans-
piration and concentration was the same as in the first series,
but in this case there was a perfectly definite maximum of
transpiration at 1.6 atm. For production of dry weight of
tops, however, while the general relation to concentration was
the same as in the first two series, the optimum concentra-
tion was 4.5 instead of 1.6 atm.
The interesting features of these results may be summar-
ized as follows: (1) Transpiration and dry weight showed
an approximately linear relation to the concentration of the
medium above the optimum, these decreasing with an increase
in concentration. (2) The optimum concentration for dry
425] 8. F. Trelease and E. E. Free
weight of tops was altered from 1.6 atm. to 4.5 atm. by chang-
ing the proportions of the four salts used in the first and third
series. (3) With the salt proportions of the three other
salts used in the first series, the omission of KC1 did not alter
the relation between growth and concentration.
THE EFFECT OF RENEWAL OF CULTURE SOLUTIONS
ON THE GROWTH OF YOUNG WHEAT PLANTS
IN WATER-CULTURES
By S. P. TKELEASE and E. E. FREE
One of the practical problems. in work with water-cultures
is that of the frequency with which the culture solution must
be renewed in order to obtain the best results. This note re-
ports experiments in this connection on the growth of young
wheat plants in the nutrient solution found by Shive x to be
best for the production of dry weight of tops In wheat. 'Mie
culture jars had a capacity of 250 cc. Six plants were grown
in each jar and each culture was in triplicate. The volume
of the culture solution was made up to normal by the addition
of distilled water every 4 days or oftener. The details of the
technique were the same as employed by SLive - Ail cultures
ran 41 days, from January 6, to February 16, 1916. The
results are given in the following table, in the form of dry
weights of tops produced, each weight being the average of
the three parallel cultures,
Dry Weight,
grams.
Changed daily . . . , , ..... „ ..... „ .„„..».... 1.243
Changed every 3 days 1.012
Changed every week 1.020
Changed after 1 week, then every 3 days . , 0.995
Changed every 2 weeks ..»».».*. ,.;. 0.780
Changed after 2 weeks, then every 3 days 1.131
Changed after 2 weeks, then every week v ...... 0.969
Changed after 1 month 0.654
Not changed at all 0.621
1 Shive, J. W., "A study of the physiological balance in nutrient
media." PhysioL Res. 1 : 327-397. 1915.
228 Renewal of Culture Solutions [42 S
It is apparent that the yield is better the more frequently
the solution is changed. If, after an initial period, the fre-
quency of changing is increased the yield is improved. It is
important, practically, that there is small difference between
the cultures changed every 3 days and those changed every
week. Daily change produces substantial improvement. Al-
lowing the solution to remain unchanged for so long as 2
weeks is markedly injurious.
The above cultures were grown on a rotating table. An
additional set was grown in the same greenhouse at the same
time but not on the rotating table. The results follow:
Dry Weight.
grams.
Continuous flow of solution through culture jar at
rate of about 1 liter daily 1.678
Changed every 3 days 1.222
Not changed at all 0.666
This experiment is not strictly comparable with the one done
•>n the rotating table, but it seems probable that continuous
flow of the solution must be regarded as more beneficial even
than daily change.
Parallel with the experiments on the rotating table, one
set of three cultures was treated by removing the solution
weekly Lnd shaking it with bone black. The solution was
then filtered and restored to the culture jars. These cul-
tures gave an average yield of 0.780 gram, as compared with
0.621 gram for the unchanged culture not treated with bone,
black. Evidently the bone black treatment improved the
solution slightly but did not correct in important degree the
harmful effects of infrequent changing. It was noticed inci-
dentally that the magnesium injury that is characteristic of
this solution, for wheat, appeared more frequently and se-
verely when the changing was frequent than when it was
not. The color of the plants was greener in the more fre-
quently changed solutions.
14 DAY USE
RETURN TO DESK FROM WHICH BORROWED
EARTH SCIENCES LIBRARY
This book is due on the last date stamped below, or
on the date to which renewed.
Renewed books are subject to immediate recall.
LD 21-40m-5,'65
(F4308slO)476
General Library
University of California
Berkeley
I
Live Music Archive
Librivox Free Audio
Metropolitan Museum
Cleveland Museum of Art
Internet Arcade
Console Living Room
Open Library
American Libraries
TV News
Understanding 9/11